Nanoparticles complexed with functionalizable enhanced affinity ligands and use thereof

ABSTRACT

Disclosed are functionalizable ligands, nanoparticles, preferably nanocrystals, complexed with ligands and their use for bio-imaging. A nano material includes a nanoparticle and at least one copolymer ligand. A ligand which is a copolymer of general formula (I): H—P[(A)x-co-(B)y]n-L-R.

FIELD OF INVENTION

The present invention relates to functionalizable ligands, nanoparticlescomplexed with said ligands, preferably nanocrystals complexed withligands, and their use for bio-imaging.

BACKGROUND OF INVENTION

Colloidal semiconductor nanoparticles, named “quantum dots” (QDs), arecrystalline objects that exhibit specific fluorescence properties. Theirabsorption cross section is very large, they are bright and theiremission spectra have a small full width half maximum, and a peakwavelength that is tunable as a function of their composition, theirsize and their shape (in the range of a few nanometers to few tens ofnanometers). They are also far more resistant to photobleaching thantraditional organic dyes. These unique features make them veryattractive for diverse applications in the field of medical andbiological imaging, such as individual proteins monitoring, multi-colorimmunostaining, stem cells tracking, fluorescence acquisition cellsorting, or optically assisted surgery.

Functionalization of QDs surface presents many advantages. Especially, asecond imaging agent may be coupled at the surface of the QD, to enablebimodal imaging. On another hand, functionalizing QDs' surface bycoupling bio-targeting moieties is interesting for bio-imaging.Functionalization by a therapeutically active molecule may also beinteresting.

QD syntheses provide colloidal solutions of fluorescent nanocrystalscapped with ligands. Functionalization of QD may thus be performed byfunctionalizing ligands presents at their surface.

Typical QD syntheses provide QDs capped with hydrophobic ligands, whilethe use of QDs in live-cell imaging requires their complete solubilityin water as well as an excellent compatibility with biological media. Tomake the QDs water-soluble, one method is to perform cap exchange,consisting in the replacement of original ligands by hydrophilic ones,bearing a chemical function able to bind to the nanocrystal surface(Chan et al. Science 1998, 281:2016 and Mattoussi et al. J. Am. Chem.Soc. 2000, 122:12142). Cap exchange results in small and stable QDs. Thenon-specific interactions of the QD with cell membranes or withbiomolecules in general depend mainly on the moieties that are adsorbedon the QD surface. Ligand exchange provides a versatile method tocontrol the size, the nature of the ligand as well as its affinity forthe QD surface (ligands that are too strong can indeed dissolve the QD,while ligands that are not strong enough can detach from the QDsurface).

Ligand desorption is a strong limitation for the use of QDs inbio-imaging. This desorption, favored in high diluted conditions, causesindeed a loss of colloidal stability and functionality, as well as anincrease in aggregation and non-specific adsorption. As a consequence,continued efforts have been made to improve the affinity of passivatingligands for the QD surface. The design of these replacing ligands isalso guided by further needs for biological applications of quantumdots, namely: small size; stability over a large pH range, at elevatedsalt concentrations and in a cellular medium; low non-specificadsorption; and possible functionalization afterwards.

To match the above-mentioned criteria, especially limitation of liganddesorption and provision of small and stable QDs, the Applicantdeveloped a multidentate zwitterionic ligand L2, issued from thecopolymerization of a bidentate monomer and a monozwitterionic monomer(Scheme 1) (Giovanelli et al. Langmuir 2012, 28, 15177-15184).

The structure of the lateral chains of L2 was evidenced to enhanceaffinity of this ligand toward QDs and thus avoid ligand desorptionwhile keeping a small size of particle.

Derivatives of L2, L2-NH₂ and L₂-PEG-NH₂ were also proposed to introducefunctionalizable amine later chains (scheme 2):

Especially, QD functionalization was performed for L2-NH₂ by conjugationwith fluorescein. L2-PEG-NH₂-capped QDs were also conjugated via theiramine function, with either biotin or avidin by peptidic coupling aftercapping QD.

Therefore, the Applicant provided a first generation of hydrophilicligands having a very good affinity for QD and being functionalizable.However, with this first generation of ligands, functionalizationrequires to use at least three different monomers to form the ligand: ananchoring monomer, an hydrophilic monomer and a functionalizablemonomer. Therefore, the resulting ligand is quite complex. Moreover, itwas evidenced that functionalization of this type of ligand modifies itsanchoring properties and therefore modifies the stability of the QD.

Therefore, there is a need for more simple ligands which remainfunctionalizable and for which functionalization does not modifyanchoring properties.

The Applicant surprisingly showed that anchoring moieties of L2 ligandmay be labile. If there is a sufficient number of anchoring functions inthe ligand, a part of them is not linked to the surface of the QD andthey may be used for functionalizing the ligand, without decreasing theanchoring stability. This presents the advantage of not requiring amodification of the ligand by a third functionalizable monomer. There isonly the need to control the length of the ligand to ensure that thereis a sufficient number of anchoring monomers to achieved both anchoringand functionalization.

Moreover, the Applicant evidenced that the ligand of the invention,which may be synthesized by radical polymerization in presence of CTA(chain transfer agent), bears one functionalizable end. Indeed, it wassurprisingly shown that upon CTA polymerization, ligands bearing at thefirst end a hydrogen atom and at the other end the CTA werepredominantly obtained, whereas numerous possibilities were expected forends of the polymeric chain.

By varying the CTA to obtain a functionalizable end of the ligand and byselecting the anchoring moiety of the anchoring monomer, orthogonalfunctionalization of the ligand may be envisaged to introduce 2 types offunctional groups on the ligand and thus on the QD. In this case, afirst functional group may be introduced at one end of the ligand, whilea second functional group may be introduced on some on the anchoringmoieties on lateral chains.

Therefore, the Applicant herein provides a new ligand of QDs, which is acopolymer obtained from at least 2 monomers, said monomers being:

-   -   one anchoring monomer A having a side-chain comprising a first        moiety M_(A) having affinity for the surface of a nanocrystal,        and    -   one hydrophilic monomer B having a side-chain comprising a        second moiety M_(B) being hydrophilic,        wherein one end of the copolymer is a hydrogen atom and the        other end comprises a functionalizable group.

The functionalizable ligand of the invention presents the advantage thateven coated on QDs, functionalizable end groups of the polymer areaccessible to conjugation. Therefore, the ligand may be functionalizedafter complexation of QD.

SUMMARY

This invention thus relates to a nanomaterial comprising:

-   -   a nanoparticle, preferably a nanocrystal; and    -   at least one ligand which is a copolymer of formula (I)

H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R

-   -   -   wherein        -   A represents an anchoring monomer having a side-chain            comprising a first moiety M_(A) having affinity for the            surface of a nanocrystal;        -   B represents a hydrophilic monomer having a side-chain            comprising a second moiety M_(B) being hydrophilic;        -   n represents a positive integer, preferably an integer            ranging from 1 to 1000, preferably from 1 to 499, from 1 to            249 or from 1 to 99;        -   x and y represent each independently a percentage of n,            wherein x and y are different from 0% of n and different            from 100% of n, preferably ranging from more than 0% to less            than 100% of n, preferably from more than 0% to 80% of n,            from more than 0% to 50% of n; wherein x+y is equal to 100%            of n;        -   R represents:            -   a functional group selected from the group comprising                —NH₂, —COOH, —OH, —SH, —CHO, ketone, halide; activated                ester such as for example N-hydroxysuccinimide ester,                N-hydroxyglutarimide ester or maleimide ester; activated                carboxylic acid such as for example acid anhydride or                acid halide; isothiocyanate; isocyanate; alkyne; azide;                glutaric anhydride, succinic anhydride, maleic                anhydride; hydrazide; chloroformate, maleimide, alkene,                silane, hydrazone, oxime and furan;            -   a bioactive group selected from the group comprising                avidin or streptavidin; antibody such as a monoclonal                antibody or a single chain antibody; sugars; a protein                or peptide sequence having a specific binding affinity                for an affinity target, such as for example an avimer or                an affibody (the affinity target may be for example a                protein, a nucleic acid, a peptide, a metabolite or a                small molecule), antigens, steroids, vitamins, drugs,                haptens, metabolites, toxins, environmental pollutants,                amino acids, peptides, proteins, aptamers, nucleic                acids, nucleotides, peptide nucleic acid (PNA), folates,                carbohydrates, lipids, phospholipid, lipoprotein,                lipopolysaccharide, liposome hormone, polysaccharide,                polymers, polyhistidine tags, fluorophores; and        -   L represents a bound or a spacer selected from the group            comprising alkylene, alkenylene, arylene or arylalkyl            linking groups having 1 to 50 chain atoms, wherein the            linking group can be optionally interrupted or terminated by            —O—, —S—, —NR₇—, wherein R₇ is H or alkyl, —CO—, —NHCO—,            —CONH— or a combination thereof; or a spacer selected from            the group comprising DNA, RNA, peptide nucleic acid (PNA),            polysaccharide, peptide.

According to one embodiment, in the nanomaterial of the invention, thenanoparticle is a nanocrystal and the nanocrystal is a 0D, 1D, or 2Dnanocrystal, preferably a nanosheet, a nanorod, a nanoplatelet, ananoplate, a nanoprism, a nanowall, a nanodisk, a nanoparticle, ananowire, a nanopowder, a nanotube, a nanotetrapod, a nanoribbon, ananobelt, a nanoneedle, a nanocube, a nanoball, a nanocoil, a nanocone,a nanopiller, a nanoflower, or a quantum dot.

According to one embodiment, in the nanomaterial of the invention, theligand is of formula (II):

-   -   wherein    -   n, x, y, L and R are as defined above;    -   R_(A) represents a group comprising the first moiety M_(A)        having affinity for the surface of a nanocrystal;    -   R_(B) represents a group comprising the second moiety M_(B)        being hydrophilic;    -   R¹, R², R³, R⁴, R⁵ and R⁶ represent each independently H or a        group selected from the alkyl, alkenyl, aryl, hydroxyl, halogen,        alkoxy and carboxylate, amide.

According to one embodiment, in the nanomaterial of the invention, theligand is of formula (I-e′):

-   -   wherein n, x, y, L and R are as defined above.

According to one embodiment, in the nanomaterial of the invention, theligand is of formula (I-f′):

-   -   wherein n, x, y and L are as defined above.

The invention further relates to a ligand which is a copolymer ofgeneral formula (I):

H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R

-   -   wherein    -   A represents an anchoring monomer having a side-chain comprising        a first moiety M_(A) having affinity for the surface of a        nanocrystal;    -   B represents a hydrophilic monomer having a side-chain        comprising a second moiety M_(B) being hydrophilic;    -   n represents a positive integer, preferably an integer ranging        from 1 to 1000, preferably from 1 to 499, from 1 to 249 or from        1 to 99;    -   x and y represent each independently a percentage of n, wherein        x and y are different from 0% of n and different from 100% of n,        preferably ranging from more than 0% to less than 100% of n,        preferably from more than 0% to 80% of n, from more than 0% to        50% of n; wherein x+y is equal to 100% of n;    -   R represents:        -   a functional group selected from the group comprising —NH₂,            —COOH, —OH, —SH, —CHO, ketone, halide; activated ester such            as for example N-hydroxysuccinimide ester,            N-hydroxyglutarimide ester or maleimide ester; activated            carboxylic acid such as for example acid anhydride or acid            halide; isothiocyanate; isocyanate; alkyne; azide; glutaric            anhydride, succinic anhydride, maleic anhydride; hydrazide;            chloroformate, maleimide, alkene, silane, hydrazone, oxime            and furan; and        -   a bioactive group selected from the group comprising avidin            or streptavidin; antibody such as a monoclonal antibody or a            single chain antibody; sugars; a protein or peptide sequence            having a specific binding affinity for an affinity target,            such as for example an avimer or an affibody (the affinity            target may be for example a protein, a nucleic acid, a            peptide, a metabolite or a small molecule), antigens,            steroids, vitamins, drugs, haptens, metabolites, toxins,            environmental pollutants, amino acids, peptides, proteins,            aptamers, nucleic acids, nucleotides, peptide nucleic acid            (PNA), folates, carbohydrates, lipids, phospholipid,            lipoprotein, lipopolysaccharide, liposome hormone,            polysaccharide, polymers, polyhistidine tags, fluorophores;            and    -   L represents a bound or a spacer selected from the group        comprising alkylene, alkenylene, arylene or arylalkyl linking        groups having 1 to 50 chain atoms, wherein the linking group can        be optionally interrupted or terminated by —O—, —S—, —NR₇—,        wherein R₇ is H or alkyl, —CO—, —NHCO—, —CONH— or a combination        thereof; or a spacer selected from the group comprising DNA,        RNA, peptide nucleic acid (PNA), polysaccharide, peptide.

According to one embodiment, the ligand of the invention is of generalformula (II):

-   -   wherein    -   n, x, y, L and R are as defined above;    -   R_(A) represents a group comprising the first moiety M_(A)        having affinity for the surface of a nanocrystal;    -   R_(B) represents a group comprising the second moiety M_(B)        being hydrophilic;    -   R¹, R², R³, R⁴, R⁵ and R⁶ represent each independently H or a        group selected from the alkyl, alkenyl, aryl, hydroxyl, halogen,        alkoxy and carboxylate, amide.

According to one embodiment, the ligand of the invention is of formula(I-e):

-   -   wherein n, x, y, L and R are as defined above.

According to one embodiment, the ligand of the invention is of formula(I-f):

-   -   wherein n, x, y and L are as defined above.

According to one embodiment, in the ligand of the invention, Lrepresents an alkylene linking group having 1 to 20 chain atoms andoptionally interrupted or terminated by —O— or —S—.

According to one embodiment, in the ligand of the invention, Rrepresents —COOH or —NH₂.

The invention also relates to a water-soluble composition comprisingnanomaterials according to the invention.

The present invention further relates to the use of a nanomaterialaccording to the invention or of the water-soluble composition accordingto the invention for bioimaging, biotargeting, medical imaging orbiosensing.

The invention also relates to a method for manufacturing the ligandaccording the invention comprising polymerizing an anchoring monomer Aand a hydrophilic monomer B in presence of an initiator and a chaintransfer agent (CTA), wherein anchoring monomer A and a hydrophilicmonomer B are as defined above.

The present invention further relates to a method for manufacturing thenanomaterial according to the invention comprising:

-   -   optionally a first step of complexation of nanocrystals with an        intermediate ligand being a weakly binding ligand or a small        molecule ensuring the homogeneous dispersion of the nanocrystal        into a solvent miscible in part with water;    -   a step of monophasic exchange at about 40° C. to about 100° C.        in an aqueous medium overnight to remove the weak intermediate        ligand and replace it by the ligand according to the invention;    -   optionally one or more subsequent steps selected from:        -   in the case wherein R represents a functional group in the            ligand of formula (I), a step of bio-conjugation to            introduce a bioactive group at the end of the polymeric            chain of the ligand;        -   functionalization of some of the M_(A) moieties of the            anchoring monomers A of the ligand by bioactive groups.

DEFINITIONS

In the present invention, the following terms have the followingmeanings:

-   -   “chain-transfer agent” refers to a substance able to react 1)        either with a radical initiator during a polymerization reaction        and the radical active center is transferred from the initiator        to said substance, allowing said substance to initiate another        radical (co)polymerization, or 2) said substance may react with        a growing macromolecular chain during a polymerization reaction        allowing transferring the radical active center from the growing        chain to said substance and thus allowing said substance the        initiation of another radical (co)polymerization.    -   “functional group” refers to a group selected from —NH₂, —COOH,        —OH, —SH, —CHO, ketone, halide; activated ester such as for        example N-hydroxysuccinimide ester, N-hydroxyglutarimide ester        or maleimide ester; activated carboxylic acid such as for        example acid anhydride or acid halide; isothiocyanate;        isocyanate; alkyne; azide; glutaric anhydride, succinic        anhydride, maleic anhydride; hydrazide; chloroformate,        maleimide, alkene, silane, hydrazone, oxime and furan.    -   “bioactive group” refers to a chemical group suitable to induce        site-specific delivery of the compound once administered. In a        preferred embodiment of the invention, the bioactive group is        selected from the group comprising avidin or streptavidin;        antibody such as a monoclonal antibody or a single chain        antibody; sugars; a protein or peptide sequence having a        specific binding affinity for an affinity target, such as for        example an avimer or an affibody (the affinity target may be for        example a protein, a nucleic acid, a peptide, a metabolite or a        small molecule), antigens, steroids, vitamins, drugs, haptens,        metabolites, toxins, environmental pollutants, amino acids,        peptides, proteins, aptamers, nucleotides, nucleic acids,        folates, carbohydrates, lipids, phospholipid, lipoprotein,        lipopolysaccharide, liposome hormone, polysaccharide, polymers,        polyhistidine tags, fluorophores.    -   “alkyl” refers to any saturated linear or branched hydrocarbon        chain, with 1 to 50 carbon atoms, preferably 1 to 6 carbon        atoms, and more preferably methyl, ethyl, propyl, isopropyl,        n-butyl, sec-butyl, isobutyl and tert-butyl. The alkyl group may        be substituted by a saturated or unsaturated aryl group.    -   When the suffix “ene” (“alkylene”) is used in conjunction with        an alkyl group, this is intended to mean the alkyl group as        defined herein having two single bonds as points of attachment        to other groups. The term “alkylene” includes methylene,        ethylene, methylmethylene, propylene, ethylethylene, and        1,2-dimethylethylene.    -   “alkenyl” refers to any linear or branched hydrocarbon chain        having at least one double bond, of 2 to 50 carbon atoms, and        preferably 2 to 6 carbon atoms. The alkenyl group may be        substituted. Examples of alkenyl groups are ethenyl, 2-propenyl,        2-butenyl, 3-butenyl, 2-pentenyl and its isomers, 2-hexenyl and        its isomers, 2,4-pentadienyl and the like. The alkenyl group may        be substituted by a saturated or unsaturated aryl group.    -   “alkynyl” refers to any linear or branched hydrocarbon chain        having at least one triple bond, of 2 to 50 carbon atoms, and        preferably 2 to 6 carbon atoms.    -   The terms “alkenylene” means an alkenyl group as defined above        having two single bonds as points of attachment to other groups.    -   “aryl” refers to a mono- or polycyclic system of 5 to 20, and        preferably 6 to 12, carbon atoms having one or more aromatic        rings (when there are two rings, it is called a biaryl) among        which it is possible to cite the phenyl group, the biphenyl        group, the 1-naphthyl group, the 2-naphthyl group, the        tetrahydronaphthyl group, the indanyl group and the binaphthyl        group. The term aryl also means any aromatic ring including at        least one heteroatom chosen from an oxygen, nitrogen or sulfur        atom. The aryl group can be substituted by 1 to 3 substituents        chosen independently of one another, among a hydroxyl group, a        linear or branched alkyl group comprising 1, 2, 3, 4, 5 or 6        carbon atoms, in particular methyl, ethyl, propyl, butyl, an        alkoxy group or a halogen atom, in particular bromine, chlorine        and iodine, a nitro group, a cyano group, an azido group, an        adhehyde group, a boronato group, a phenyl, CF₃, methylenedioxy,        ethylenedioxy, SO₂NRR′, NRR′, COOR (where R and R′ are each        independently selected from the group consisting of H and        alkyl), an second aryl group which may be substituted as above.        Non-limiting examples of aryl comprise phenyl, biphenylyl,        biphenylenyl, 5- or 6-tetralinyl, naphthalen-1- or -2-yl, 4-,        5-, 6 or 7-indenyl, 1- 2-, 3-, 4- or 5-acenaphtylenyl, 3-, 4- or        5-acenaphtenyl, 1- or 2-pentalenyl, 4- or 5-indanyl, 5-, 6-, 7-        or 8-tetrahydronaphthyl, 1,2,3,4-tetrahydronaphthyl,        1,4-dihydronaphthyl, 1-, 2-, 3-, 4- or 5-pyrenyl.    -   The term “arylene” as used herein is intended to include        divalent carbocyclic aromatic ring systems such as phenylene,        biphenylylene, naphthylene, indenylene, pentalenylene,        azulenylene and the like.    -   “cycle” refers to a saturated, partially unsaturated or        unsaturated cyclic group.    -   “heterocycle” refers to a saturated, partially unsaturated or        unsaturated cyclic group comprising at least on heteroatom.    -   “halogen” means fluoro, chloro, bromo, or iodo. Preferred halo        groups are fluoro and chloro.    -   “alkoxy” refers to any O-alkyl group, preferably an O-alkyl        group wherein the alkyl group has 1 to 6 carbon atoms.    -   “aryloxy” refers to any O-aryl group.    -   “arylalkyl” refers to an alkyl group substituted by an aryl        group, such as for example the phenyl-methyl group.    -   “arylalkoxy” refers to an alkoxy group substituted by an aryl        group.    -   “amine” refers to any group derived from ammoniac NH₃ by        substitution of one or more hydrogen atoms with an organic        radical.    -   “azido” refers to —N₃ group.    -   “acidic function” refers to —COOH group.    -   “activated acidic function” refers to an acidic function wherein        the —OH is replaced by a better leaving group.    -   “activated alcoholic function” refers to an alcoholic function        modified to be a better leaving group.    -   “hydrophilic” refers to a molecule or portion of a molecule that        has a tendency to interact with or be dissolved by water and        other polar substances.

DETAILED DESCRIPTION

The present invention relates to a ligand which is a copolymer obtainedfrom at least 2 monomers, said monomers being:

-   -   one anchoring monomer A having a side-chain comprising a first        moiety M_(A) having affinity for the surface of a material; and    -   one hydrophilic monomer B having a side-chain comprising a        second moiety M_(B) being hydrophilic;        and wherein one end of copolymer is H and the other end        comprises a functional group or a bioactive group.

In one embodiment, the material for which the first moiety M_(A) hasaffinity, is selected from the group comprising metals, semiconductors,oxides, lanthanides or mixtures thereof.

In one embodiment, the material is preferably selected from gold, iron,silver, copper, aluminum, platinum, lead, palladium, iron oxide,titanium dioxide, cerium oxide, metal chalcogenide, metal pnictide,cadmium, zinc, magnesium, mercury, gallium, indium, thallium, cobalt,tin or mixtures thereof.

In a specific embodiment, the material for which the first moiety M_(A)has affinity, is under the form of particles, preferably nanoparticles.According to one embodiment, nanoparticles may be nanocrystals.

Especially, the present invention relates to a ligand which is acopolymer obtained from at least 2 monomers, said monomers being:

-   -   one anchoring monomer A having a side-chain comprising a first        moiety M_(A) having affinity for the surface of a nanocrystal;        and    -   one hydrophilic monomer B having a side-chain comprising a        second moiety M_(B) being hydrophilic;        and wherein one end of copolymer is H and the other end        comprises a functional group or a bioactive group.

According to one embodiment, the functional group is selected from thegroup comprising —NH₂, —COOH, —OH, —SH, —CHO, ketone, halide; activatedester such as for example N-hydroxysuccinimide ester,N-hydroxyglutarimide ester or maleimide ester; activated carboxylic acidsuch as for example acid anhydride or acid halide; isothiocyanate;isocyanate; alkyne; azide; glutaric anhydride, succinic anhydride,maleic anhydride; hydrazide; chloroformate, maleimide, alkene, silane,hydrazone, oxime and furan.

According to an embodiment, the bioactive group is selected from thegroup comprising avidin or streptavidin; antibody such as a monoclonalantibody or a single chain antibody; sugars; a protein or peptidesequence having a specific binding affinity for an affinity target, suchas for example an avimer or an affibody (the affinity target may be forexample a protein, a nucleic acid, a peptide, a metabolite or a smallmolecule), antigens, steroids, vitamins, drugs, haptens, metabolites,toxins, environmental pollutants, amino acids, peptides, proteins,aptamers, nucleic acids, nucleotides, peptide nucleic acid (PNA),folates, carbohydrates, lipids, phospholipid, lipoprotein,lipopolysaccharide, liposome hormone, polysaccharide, polymers,polyhistidine tags, fluorophores.

In an embodiment of the invention monomers A and B are methacrylamidemonomers.

In one embodiment, the first moiety M_(A) having affinity for thesurface of a nanocrystal has preferably affinity for a metal present atthe surface of a nanocrystal or for a material E present at the surfaceof a nanocrystal and selected in the group of O, S, Se, Te, N, P, As,and mixture thereof.

Examples of metal present at the surface of a nanocrystal include, butare not limited to, gold, iron oxide, titanium dioxide, cerium oxide,metal chalcogenide, metal pnictide, cadmium, zinc, magnesium, mercury,aluminium, gallium, indium, thallium, copper, cobalt, platinum, silver,tin, lead and mixtures thereof.

In one embodiment, the ligand of the invention is a copolymer having aplurality of monomers including monomer A and monomer B. In oneembodiment, said ligand is a random, alternate or block copolymer. Inanother embodiment, the ligand is a statistic copolymer. In anotherembodiment, said ligand is a random or block copolymer consistingessentially of monomer A and monomer B. In one embodiment of theinvention, said ligand is a multi-dentate ligand.

According to one embodiment, preferred monomers A are those described inthe following table:

Compound n° Name A15-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)pentanamide A26-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)hexanamide A37-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)heptanamide A48-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)octanamide A59-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)nonanamide A610-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)decanamide A75-(1,2-dithiolan-3-yl)-N-(3-acrylamidopropyl)pentanamide A86-(1,2-dithiolan-3-yl)-N-(3-acrylamidopropyl)hexanamide A97-(1,2-dithiolan-3-yl)-N-(3-acrylamidopropyl)heptanamide A108-(1,2-dithiolan-3-yl)-N-(3-acrylamidopropyl)octanamide A119-(1,2-dithiolan-3-yl)-N-(3-acrylamidopropyl)nonanamide A1210-(1,2-dithiolan-3-yl)-N-(3-acrylamidopropyl)decanamide A133-(5-(1,2-dithiolan-3-yl)pentanamido)propyl methacrylate A143-(6-(1,2-dithiolan-3-yl)hexanamido)propyl methacrylate A153-(7-(1,2-dithiolan-3-yl)heptanamido)propyl methacrylate A163-(8-(1,2-dithiolan-3-yl)octanamido)propyl methacrylate A173-(9-(1,2-dithiolan-3-yl)nonanamido)propyl methacrylate A183-(10-(1,2-dithiolan-3-yl)decanamido)propyl methacrylate A193-(11-(1,2-dithiolan-3-yl)pentanamido)propyl acrylate A203-(6-(1,2-dithiolan-3-yl)hexanamido)propyl acrylate A213-(7-(1,2-dithiolan-3-ylheptamido)propyl acrylate A223-(8-(1,2-dithiolan-3-yl)octanamido)propyl acrylate A233-(9-(1,2-dithiolan-3-yl)nonanamido)propyl acrylate A243-(10-(1,2-dithiolan-3-yl)decanamido)propyl acrylate A255-mercapto-N-(3-methacrylamidopropyl)pentanamide A266-mercapto-N-(3-methacrylamidopropyl)hexanamide A277-mercapto-N-(3-methacrylamidopropyl)heptanamide A288-mercapto-N-(3-methacrylamidopropyl)octanamide A299-mercapto-N-(3-methacrylamidopropyl)nonanamide A3010-mercapto-N-(3-methacrylamidopropyl)decanamide A31N-(3-acrylamidopropyl)-5-mercaptopentanamide A32N-(3-acrylamidopropyl)-6-mercaptohexanamide A33N-(3-acrylamidopropyl)-7-mercaptoheptanamide A34N-(3-acrylamidopropyl)-8-mercaptooctanamide A35N-(3-acrylamidopropyl)-9-mercaptononanamide A36N-(3-acrylamidopropyl)-10-mercaptodecanamide A373-(5-mercaptopentanamido)propyl methacrylate A383-(6-mercaptohexanamido)propyl methacrylate A393-(7-mercaptoheptanamido)propyl methacrylate A403-(8-mercaptooctanamido)propyl methacrylate A413-(9-mercaptononanamido)propyl methacrylate A423-(10-mercaptodecanamido)propyl methacrylate A433-(5-mercaptopentanamido)propyl acrylate A443-(6-mercaptohexanamido)propyl acrylate A453-(7-mercaptoheptanamido)propyl acrylate A463-(8-mercaptooctanamido)propyl acrylate A473-(9-mercaptononanamido)propyl acrylate A483-(10-mercaptodecanamido)propyl acrylate A495-((3-methacrylamidopropyl)amino)-5-oxopentanoic acid A506-((3-methacrylamidopropyl)amino)-6-oxohexanoic acid A517-((3-methacrylamidopropyl)amino)-7-oxoheptanoic acid A528-((3-methacrylamidopropyl)amino)-8-oxooctanoic acid A539-((3-methacrylamidopropyl)amino)-9-oxononanoic acid A5410-((3-methacrylamidopropyl)amino)-10-oxodecanoic acid A555-((3-acrylamidopropyl)amino)-5-oxopentanoic acid A566-((3-acrylamidopropyl)amino)-6-oxohexanoic acid A577-((3-acrylamidopropyl)amino)-7-oxoheptanoic acid A588-((3-acrylamidopropyl)amino)-8-oxooctanoic acid A599-((3-acrylamidopropyl)amino)-9-oxononanoic acid A6010-((3-acrylamidopropyl)amino)-10-oxodecanoic acid A615-((3-(methacryloyloxy)propyl)amino)-5-oxopentanoic acid A626-((3-(methacryloyloxy)propyl)amino)-6-oxohexanoic acid A637-((3-(methacryloyloxy)propyl)amino)-7-oxoheptanoic acid A648-((3-(methacryloyloxy)propyl)amino)-8-oxooctanoic acid A659-((3-(methacryloyloxy)propyl)amino)-9-oxononanoic acid A6610-((3-(methacryloyloxy)propyl)amino)-10-oxodecanoic acid A675-((3-(acryloyloxy)propyl)amino)-5-oxopentanoic acid A686-((3-(acryloyloxy)propyl)amino)-6-oxohexanoic acid A697-((3-(acryloyloxy)propyl)amino)-7-oxoheptanoic acid A708-((3-(acryloyloxy)propyl)amino)-8-oxooctanoic acid A719-((3-(acryloyloxy)propyl)amino)-9-oxononanoic acid A7210-((3-(acryloyloxy)propyl)amino)-10-oxodecanoic acid A735-amino-N-(3-methacrylamidopropyl)pentanamide A746-amino-N-(3-methacrylamidopropyl)hexanamide A757-amino-N-(3-methacrylamidopropyl)heptanamide A768-amino-N-(3-methacrylamidopropyl)octanamide A779-amino-N-(3-methacrylamidopropyl)nonanamide A7810-amino-N-(3-methacrylamidopropyl)decanamide A79N-(3-acrylamidopropyl)-5-aminopentanamide A80N-(3-acrylamidopropyl)-6-aminohexanamide A81N-(3-acrylamidopropyl)-7-aminheptanamide A82N-(3-acrylamidopropyl)-8-aminooctanamide A83N-(3-acrylamidopropyl)-9-aminononanamide A84N-(3-acrylamidopropyl)-10-aminodecanamide A853-(5-aminopentanamido)propyl methacrylate A863-(6-aminohexanamido)propyl methacrylate A873-(7-aminoheptanamido)propyl methacrylate A883-(8-aminooctanamido)propyl methacrylate A89 3-(9-aminononamido)propylmethacrylate A90 3-(10-aminodecanamido)propyl methacrylate A913-(5-aminopentanamido)propyl acrylate A92 3-(6-aminohexanamido)propylacrylate A93 3-(7-aminoheptanamido)propyl acrylate A943-(8-aminooctanamido)propyl acrylate A95 3-(9-aminononamido)propylacrylate A96 3-(10-aminodecanamido)propyl acrylate

According to one embodiment, preferred monomers B are those described inthe following table:

Compound n° Name B1 3-((3-methacrylamidopropyl)dimethylammonio)propane-1-sulfonate B2 5-((3-methacrylamidopropyl)dimethylammonio)pentane-1-sulfonate B3 6-((3-methacrylamidopropyl)dimethylammonio)hexane-1-sulfonate B4 7-((3-methacrylamidopropyl)dimethylammonio)heptane-1-sulfonate B5 8-((3-methacrylamidopropyl)dimethylammonio)octane-1-sulfonate B6 9-((3-methacrylamidopropyl)dimethylammonio)nonane-1-sulfonate B7 10-((3-methacrylamidopropyl)dimethylammonio)decane-1-sulfonate B8 3-((4-methacrylamidobutyl)dimethylammonio)propane-1-sulfonate B9 3-((5-methacrylamidopentyl)dimethylammonio)propane-1-sulfonate B10 3-((6-methacrylamidohexyl)dimethylammonio)propane-1-sulfonate B11 3-((7-methacrylamidoheptyl)dimethylammonio)propane-1-sulfonate B12 3-((8-methacrylamidooctyl)dimethylammonio)propane-1-sulfonate B13 3-((9-methacrylamidononyl)dimethylammonio)propane-1-sulfonate B14 3-((10-methacrylamidodecyl)dimethylammonio)propane-1-sulfonate B15 3-((3-acrylamidopropyl)dimethylammonio)propane-1-sulfonate B16 5-((3-acrylamidopropyl)dimethylammonio)pentane-1-sulfonate B17 6-((3-acrylamidopropyl)dimethylammonio)hexane-1-sulfonate B18 7-((3-acrylamidopropyl)dimethylammonio)heptane-1-sulfonate B19 8-((3-acrylamidopropyl)dimethylammonio)octane-1-sulfonate B20 9-((3-acrylamidopropyl)dimethylammonio)nonane-1-sulfonate B21 10((3-acrylamidopropyl)dimethylammonio)decane-1-sulfonate B22 3-((4-acrylamidobutyl)dimethylammonio)propane-1-sulfonate B23 3-((5-acrylamidopentyl)dimethylammonio)propane-1-sulfonate B24 3-((6-acrylamidohexyl)dimethylammonio)propane-1-sulfonate B25 3-((7-acrylamidoheptyl)dimethylammonio)propane-1-sulfonate B26 3-((8-acrylamidooctyl)dimethylammonio)propane-1-sulfonate B27 3-((9-acrylamidononyl)dimethylammonio)propane-1-sulfonate B28 3-((10-acrylamidodecyl)dimethylammonio)propane-1-sulfonate B29 3-((3-(methacryloyloxy)propyl)dimethylammonio)propane-1-sulfonate B30 5-((3-(methacryloyloxy)propyl)dimethylammonio)pentane-1-sulfonate B31 6-((3-(methacryloyloxy)propyl)dimethylammonio)hexane-1-sulfonate B32 7-((3-(methacryloyloxy)propyl)dimethylammonio)heptane-1-sulfonate B33 8-((3-(methacryloyloxy)propyl)dimethylammonio)octane-1-sulfonate B34 9-((3-(methacryloyloxy)propyl)dimethylammonio)nonane-1-sulfonate B35 10-((3-(methacryloyloxy)propyl)dimethylammonio)decane-1-sulfonate B36 3-((4-(methacryloyloxy)butyl)dimethylammonio)propane-1-sulfonate B37 3-((5-(methacryloyloxy)pentyl)dimethylammonio)propane-1-sulfonate B38 3-((6-(methacryloyloxy)hexyl)dimethylammonio)propane-1-sulfonate B39 3-((7-(methacryloyloxy)heptyl)dimethylammonio)propane-1-sulfonate B40 3-((8-(methacryloyloxy)octyl)dimethylammonio)propane-1-sulfonate B41 3-((9-(methacryloyloxy)nonyl)dimethylammonio)propane-1-sulfonate B42 3-((10-(methacryloyloxy)decyl)dimethylammonio)propane-1-sulfonate B43 3-((3-(acryloyloxy)propyl)dimethylammonio)propane-1-sulfonate B44 5-((3-(acryloyloxy)propyl)dimethylammonio)pentane-1-sulfonate B45 6-((3-(acryloyloxy)propyl)dimethylammonio)hexane-1-sulfonate B46 7-((3-(acryloyloxy)propyl)dimethylammonio)heptane-1-sulfonate B47 8-((3-(acryloyloxy)propyl)dimethylammonio)octane-1-sulfonate B48 9-((3-(acryloyloxy)propyl)dimethylammonio)nonane-1-sulfonate B49 10-((3-(acryloyloxy)propyl)dimethylammonio)decane-1-sulfonate B50 3-((4-(acryloyloxy)butyl)dimethylammonio)propane-1-sulfonate B51 3-((5-(acryloyloxy)pentyl)dimethylammonio)propane-1-sulfonate B52 3-((6-(acryloyloxy)hexyl)dimethylammonio)propane-1-sulfonate B53 3-((7-(methacryloyloxy)heptyl)dimethylammonio)propane-1-sulfonate B54 3-((8-(acryloyloxy)octyl)dimethylammonio)propane-1-sulfonate B55 3-((9-(acryloyloxy)nonyl)dimethylammonio)propane-1-sulfonate B56 3-((10-(acryloyloxy)decyl)dimethylammonio)propane-1-sulfonate B574-((3-methacrylamidopropyl)dimethylammonio)butanoate B585-((3-methacrylamidopropyl)dimethylammonio)pentanoate B596-((3-methacrylamidopropyl)dimethylammonio)hexanoate B607-((3-methacrylamidopropyl)dimethylammonio)heptanoate B618-((3-methacrylamidopropyl)dimethylammonio)octanoate B629-((3-methacrylamidopropyl)dimethylammonio)nonanoate B6310-((3-methacrylamidopropyl)dimethylammonio)decanoate B644-((4-methacrylamidobutyl)dimethylammonio)butanoate B654-((5-methacrylamidopentyl)dimethylammonio)butanoate B664-((6-methacrylamidohexyl)dimethylammonio)butanoate B674-((7-methacrylamidoheptyl)dimethylammonio)butanoate B684-((8-methacrylamidooctyl)dimethylammonio)butanoate B694-((9-methacrylamidononyl)dimethylammonio)butanoate B704-((10-methacrylamidodecyl)dimethylammonio)butanoate B714-((3-acrylamidopropyl)dimethylammonio)butanoate B725-((3-acrylamidopropyl)dimethylammonio)pentanoate B736-((3-acrylamidopropyl)dimethylammonio)hexanoate B747-((3-acrylamidopropyl)dimethylammonio)heptanoate B758-((3-acrylamidopropyl)dimethylammonio)octanoate B769-((3-acrylamidopropyl)dimethylammonio)nonanoate B7710-((3-acrylamidopropyl)dimethylammonio)decanoate B784-((4-acrylamidobutyl)dimethylammonio)butanoate B794-((5-acrylamidopentyl)dimethylammonio)butanoate B804-((6-acrylamidohexyl)dimethylammonio)butanoate B814-((7-acrylamidoheptyl)dimethylammonio)butanoate B824-(8-acrylamidooctyl)dimethylammonio)butanoate B834-(9-acrylamidononyl)dimethylammonio)butanoate B844-((10-acrylamidodecyl)dimethylammonio)butanoate B854-((3-methacryloyloxypropyl)dimethylammonio)butanoate B865-((3-methacryloyloxypropyl)dimethylammonio)pentanoate B876-((3-methacryloyloxypropyl)dimethylammonio)hexanoate B887-((3-methacryloyloxypropyl)dimethylammonio)heptanoate B898-((3-methacryloyloxypropyl)dimethylammonio)octanoate B909-((3-methacryloyloxypropyl)dimethylammonio)nonanoate B9110-((3-methacryloyloxypropyl)dimethylammonio)decanoate B924-((4-methacryloyloxybutyl)dimethylammonio)butanoate B934-((5-methacryloyloxpentyl)dimethylammonio)butanoate B944-((6-methacryloyloxyhexyl)dimethylammonio)butanoate B954-((7-methacryloyloxyheptyl)dimethylammonio)butanoate B964-(9-methacryloyloxynonyl)dimethylammonio)butanoate B974-((10-methacryloyloxydecyl)dimethylammonio)butanoate B984-((3-acryloyloxypropyl)dimethylammonio)butanoate B995-((3-acryloyloxypropyl)dimethylammonio)pentanoate B1006-((3-acryloyloxypropyl)dimethylammonio)hexanoate B1017-((3-acryloyloxypropyl)dimethylammonio)heptanoate B1028-((3-acryloyloxypropyl)dimethylammonio)octanoate B1039-((3-acryloyloxypropyl)dimethylammonio)nonanoate B10410-((3-acryloyloxypropyl)dimethylammonio)decanoate B1054-((4-acryloyloxybutyl)dimethylammonio)butanoate B1064-((5-acryloyloxypentyl)dimethylammonio)butanoate B1074-((6-acryloyloxyhexyl)dimethylammonio)butanoate B1084-((7-acryloyloxyheptyl)dimethylammonio)butanoate B1094-((9-acryloyloxynonyl)dimethylammonio)butanoate B1104-((10-acryloyloxydecyl)dimethylammonio)butanoate

According to one embodiment, preferred -L-R are those described in thefollowing table:

Compound n° Chemical structure LR1 —S—(CH₂)₂—(O—CH₂—CH2)₈—COOH LR2—S—(CH₂)₃—(O—CH₂—CH₂)₈—COOH LR3 —S—(CH₂)₄—(O—CH₂—CH₂)₈—COOH LR4—S—(CH₂)₅—(O—CH₂—CH₂)₈—COOH LR5 —S—(CH₂)₆—(O—CH₂—CH₂)₈—COOH LR6—S—(CH₂)₇—(O—CH₂—CH₂)₈—COOH LR7 —S—(CH₂)₈—(O—CH₂—CH₂)₈—COOH LR8—S—(CH₂)₉—(O—CH₂—CH₂)₈—COOH LR9 —S—(CH₂)₁₀—(O—CH₂—CH₂)₈—COOH LR10—S—(CH₂)₂—(O—CH₂—CH₂)₉—COOH LR11 —S—(CH₂)₂—(O—CH₂—CH₂)₁₀—COOH LR12—S—(CH₂)₂—(O—CH₂—CH₂)₁₁—COOH LR13 —S—(CH₂)₂—(O—CH₂—CH₂)₁₂—COOH LR14—S—(CH₂)₂—(O—CH₂—CH₂)₁₃—COOH LR15 —S—(CH₂)₂—(O—CH₂—CH₂)₁₄—COOH LR16—S—(CH₂)₂—(O—CH₂—CH₂)₁₅—COOH LR17 —S—(CH₂)₂—(O—CH₂—CH₂)₁₆—COOH LR18—S—(CH₂)₂—(O—CH₂—CH₂)₁₇—COOH LR19 —S—(CH₂)₂—(O—CH₂—CH₂)₁₈—COOH LR20—S—(CH₂)₂—(O—CH₂—CH₂)₁₉—COOH LR21 —S—(CH₂)₂—(O—CH₂—CH₂)₂₀—COOH LR22—S—(CH₂)₂—(O—CH₂—CH₂)₈—CO—NHS LR23 —S—(CH₂)₃—(O—CH₂—CH₂)₈—CO—NHS LR24—S—(CH₂)₄—(O—CH₂—CH₂)₈—CO—NHS LR25 —S—(CH₂)₅—(O—CH₂—CH₂)₈—CO—NHS LR26—S—(CH₂)₆—(O—CH₂—CH₂)₈—CO—NHS LR27 —S—(CH₂)₇—(O—CH₂—CH₂)₈—CO—NHS LR28—S—(CH₂)₈—(O—CH₂—CH₂)₈—CO—NHS LR29 —S—(CH₂)₉—(O—CH₂—CH₂)₈—CO—NHS LR30—S—(CH₂)₁₀—(O—CH₂—CH₂)₈—COOH LR31 —S—(CH₂)₂—(O—CH₂—CH₂)₉—CO—NHS LR32—S—(CH₂)₂—(O—CH₂—CH₂)₁₀—CO—NHS LR33 —S—(CH₂)₂—(O—CH₂—CH₂)₁₁—CO—NHS LR34—S—(CH₂)₂—(O—CH₂—CH₂)₁₂—CO—NHS LR35 —S—(CH₂)₂—(O—CH₂—CH₂)₁₃—CO—NHS LR36—S—(CH₂)₂—(O—CH₂—CH₂)₁₄—CO—NHS LR37 —S—(CH₂)₂—(O—CH₂—CH₂)₁₅—CO—NHS LR38—S—(CH₂)₂—(O—CH₂—CH₂)₁₆—CO—NHS LR39 —S—(CH₂)₂—(O—CH₂—CH₂)₁₇—CO—NHS LR40—S—(CH₂)₂—(O—CH₂—CH₂)₁₈—CO—NHS LR41 —S—(CH₂)₂—(O—CH₂—CH₂)₁₉—CO—NHS LR42—S—(CH₂)₂—(O—CH₂—CH₂)₂₀—CO—NHS LR43 —S—(CH₂)₃—COOH LR44 —S—(CH₂)₄—COOHLR45 —S—(CH₂)₅—COOH LR46 —S—(CH₂)₆—COOH LR47 —S—(CH₂)₇—COOH LR48—S—(CH₂)₈—COOH LR49 —S—(CH₂)₉—COOH LR50 —S—(CH₂)₁₀—COOH LR51—S—(CH₂)₃—CO—NHS LR52 —S—(CH₂)₄—CO—NHS LR53 —S—(CH₂)₅—CO—NHS LR54—S—(CH₂)₆—CO—NHS LR55 —S—(CH₂)₇—CO—NHS LR56 —S—(CH₂)₈—CO—NHS LR57—S—(CH₂)₉—CO—NHS LR58 —S—(CH₂)₁₀—CO—NHS

Commonly used nomenclature for a copolymer comprising a total of nmonomers, x % of said monomers being monomer A and y % of said monomersbeing monomer B is: P[A_(x)-co-B_(y)]_(n). When the extremities of thecopolymer are specific, they may be indicated on either side ofP[A_(x)-co-B_(y)]_(n), namely under the form:R¹—P[A_(x)-co-B_(y)]_(n)—R². This nomenclature is used hereafter for thecopolymer of the invention.

According to one embodiment, the ligand of the present invention is acopolymer of general formula (I):

H—P-[(A)_(x)-co-(B)_(y)]_(n)-L-R

-   -   wherein    -   A represents an anchoring monomer having a side-chain comprising        a first moiety M_(A) having affinity for the surface of a        nanocrystal;    -   B represents a hydrophilic monomer having a side-chain        comprising a second moiety M_(B) being hydrophilic;    -   n represents a positive integer, preferably an integer ranging        from 1 to 1000, preferably from 1 to 499, from 1 to 249 or from        1 to 99;    -   x and y represent each independently a percentage of n, wherein        x and y are different from 0% of n and different from 100% of n,        preferably ranging from more than 0% to less than 100% of n,        preferably from more than 0% to 80% of n, from more than 0% to        50% of n; wherein x+y is equal to 100% of n;    -   R represents:        -   a functional group selected from the group comprising —NH₂,            —COOH, —OH, —SH, —CHO, ketone, halide; activated ester such            as for example N-hydroxysuccinimide ester,            N-hydroxyglutarimide ester or maleimide ester; activated            carboxylic acid such as for example acid anhydride or acid            halide; isothiocyanate; isocyanate; alkyne; azide; glutaric            anhydride, succinic anhydride, maleic anhydride; hydrazide;            chloroformate, maleimide, alkene, silane, hydrazone, oxime            and furan; and        -   a bioactive group selected from the group comprising avidin            or streptavidin; antibody such as a monoclonal antibody or a            single chain antibody; sugars; a protein or peptide sequence            having a specific binding affinity for an affinity target,            such as for example an avimer or an affibody (the affinity            target may be for example a protein, a nucleic acid, a            peptide, a metabolite or a small molecule), antigens,            steroids, vitamins, drugs, haptens, metabolites, toxins,            environmental pollutants, amino acids, peptides, proteins,            aptamers, nucleic acids, nucleotides, peptide nucleic acid            (PNA), folates, carbohydrates, lipids, phospholipid,            lipoprotein, lipopolysaccharide, liposome hormone,            polysaccharide, polymers, polyhistidine tags, fluorophores;            and L represents a bound or a spacer selected from the group            comprising alkylene, alkenylene, arylene or arylalkyl            linking groups having 1 to 50 chain atoms, wherein the            linking group can be optionally interrupted or terminated by            —O—, —S—, —NR₇—, wherein R₇ is H or alkyl, —CO—, —NHCO—,            —CONH— or a combination thereof; or a spacer selected from            the group comprising DNA, RNA, peptide nucleic acid (PNA),            polysaccharide, peptide.

In a preferred embodiment of the invention, R represents —COOH or —NH₂.

In a specific embodiment of the invention, L represents an alkylenelinking group having 1 to 20 chain atoms, preferably 1 to 12 chainatoms, preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 chain atoms,and optionally interrupted or terminated by —O— or —S—.

In one embodiment, L is of formula —S—(CH₂)_(n1)—, wherein n₁ is apositive integer ranging from 1 to 20, preferably 1 to 5, morepreferably 1, 2 or 3.

In a specific embodiment of the invention, L represents an alkylenelinking group having 3 to 20 chain atoms, preferably 3 to 12 chainatoms, preferably 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 chain atoms, andoptionally interrupted or terminated by —O— or —S—.

In one embodiment, L is of formula —S—(CH₂)_(n1)—, wherein n₁ is apositive integer higher than 2, preferably 3 to 12 chain atoms,preferably 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 chain atoms.

In another embodiment, L represents an ethylene glycol derivative,preferably of formula —[CH₂—CH₂—O]_(n2)—(CH₂)_(n3)—S— wherein n₂ and n₃are each independently positive integers and n₂+n₃ is higher than 2;preferably n₂+n₃ is ranging from 3 to 230. In one embodiment, Lrepresents an ethylene glycol derivative, preferably of formula—[CH₂—CH₂—O]_(n2)—(CH₂)_(n3)—S— wherein n₂ and n₃ are each independentlypositive integers and n₂+n₃ is ranging from 3 to 120; preferably is 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94,95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,110, 111, 112, 113, 114, 115, 116, 117, 118, 119 and 120.

In one embodiment, L represents an ethylene glycol derivative,preferably of formula —[CH₂—CH₂—O]_(n2)—(CH₂)_(n3)—S— wherein n₂ and n₃are each independently positive integers and n₂+n₃ is ranging from 3 to50; preferably is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 and 50.

In another embodiment, L represents an ethylene glycol derivative,preferably of formula —[CH₂—CH₂—O]_(n2)—(CH₂)_(n3)—S— wherein n₂ and n₃are each independently positive integers ranging from 1 to 20,preferably 1, 2, 3, 4, 5, 6 7, 8, 9 or 10, more preferably n₂ is equalto 8 and n₃ is equal to 2.

In another embodiment, L represents a poly(ethylene glycol) derivativehaving a molecular weight less than 10 000 g/mol; preferably less than 5000 g/mol; more preferably less than 1 000 g/mol.

In one embodiment, L represents a poly(ethylene glycol) derivativehaving a molecular weight ranging from 300 g/mol to 1 000 g/mol. In oneembodiment, L represents a poly(ethylene glycol) derivative having amolecular weight ranging from 44 g/mol to 300 g/mol.

In one embodiment, L represents a poly(ethylene glycol) derivativehaving a molecular weight of about 400 g/mol.

In one embodiment, L represents a poly(ethylene glycol) derivativehaving a molecular weight of about 300 g/mol.

In another embodiment, -L-R represents—S—(CH₂)_(n3)—[CH₂—CH₂—O]_(n2)—COOH wherein n₂ and n₃ are eachindependently positive integers and n₂+n₃ is higher than 2; preferablyn₂+n₃ is ranging from 3 to 230; more preferably ranging from 5 to 115:more preferably n₂ is equal to 8 and n₃ is equal to 2.

In another embodiment, -L-R does not represent —S—(CH₂)_(n3)—COOHwherein n₃ is ranging from 1 to 11.

In another embodiment, -L-R does not represent —S—(CH₂)_(n3)—NH₂ whereinn₃ is ranging from 2 to 11.

In one embodiment of the invention, n is ranging from 1 to 1000, from 1to 499, from 1 to 249, from 1 to 99, from 5 to 75, from 5 to 50, from 10to 50, from 10 to 30, from 5 to 35, from 5 to 25, from 15 to 25.

In one embodiment, x and y are each independently a percentage of n,preferably a percentage selected in the group of 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,45, 46, 47, 48, 49, 50% of n.

According to an embodiment, the ligand of the present invention is acopolymer of general formula (II):

-   -   wherein    -   n, x, y, L and R are as defined in formula (I);    -   R_(A) represents a group comprising the first moiety M_(A)        having affinity for the surface of a nanocrystal;    -   R_(B) represents a group comprising the second moiety M_(B)        being hydrophilic;    -   R¹, R², R³, R⁴, R⁵ and R⁶ represent each independently H or a        group selected from the alkyl, alkenyl, aryl, hydroxyl, halogen,        alkoxy and carboxylate, amide.

In one embodiment of the invention, R², R³, R⁵ and R⁶ are H.

In one embodiment of the invention, R¹ and R⁴ are alkyl groups,preferably methyl.

In one embodiment of the invention, said first moiety M_(A) havingaffinity for the surface of a nanocrystal and in particular affinity fora metal present at the surface of a nanocrystal includes, but is notlimited to, a thiol moiety, a dithiol moiety, an imidazole moiety, acatechol moiety, a pyridine moiety, a pyrrole moiety, a thiophenemoiety, a thiazole moiety, a pyrazine moiety, a carboxylic acid orcarboxylate moiety, a naphthyridine moiety, a phosphine moiety, aphosphine oxide moiety, a phenol moiety, a primary amine moiety, asecondary amine moiety, a tertiary amine moiety, a quaternary aminemoiety, an aromatic amine moiety, or a combination thereof.

In one embodiment of the invention, said first moiety M_(A) havingaffinity for the surface of a nanocrystal and in particular affinity fora material E selected in the group of O, S, Se, Te, N, P, As, andmixture thereof, includes, but is not limited to, an imidazole moiety, apyridine moiety, a pyrrole moiety, a thiazole moiety, a pyrazine moiety,a naphthyridine moiety, a phosphine moiety, a phosphine oxide moiety, aprimary amine moiety, a secondary amine moiety, a tertiary amine moiety,a quaternary amine moiety, an aromatic amine moiety, or a combinationthereof.

In one embodiment of the invention, said first moiety M_(A) havingaffinity for the surface of a nanocrystal is a dithiol moiety,preferably a propane-1,3-dithiol, more preferably apropan-1-yl-1,3-dithiol moiety.

In one embodiment of the invention, said second moiety M_(B) beinghydrophilic includes, but is not limited to, a zwitterionic moiety (i.e.any compound having both a negative charge and a positive charge,preferably a group with both an ammonium group and a sulfonate group ora group with both an ammonium group and a carboxylate group) such as forexample an aminocarboxylate, an aminosulfonate, a carboxybetaine moietywherein the ammonium group may be included in an aliphatic chain, afive-membered cycle, a five-membered heterocycle comprising 1, 2 or 3further nitrogen atoms, a six-membered cycle, a six-membered heterocyclecomprising 1, 2, 3 or 4 further nitrogen atoms, a sulfobetaine moietywherein the ammonium group may be included in an aliphatic chain, afive-membered cycle, a five-membered heterocycle comprising 1, 2 or 3further nitrogen atoms, a six-membered cycle, a six-membered heterocyclecomprising 1, 2, 3 or 4 further nitrogen atoms, a phosphobetaine whereinthe ammonium group may be included in an aliphatic chain, afive-membered cycle, a five-membered heterocycle comprising 1, 2 or 3further nitrogen atoms, a six-membered cycle, a six-membered heterocyclecomprising 1, 2, 3 or 4 further nitrogen atoms, a phosphorylcholine, aphosphocholine moiety, and combinations thereof or a PEG moiety orpoly(ether)glycol moiety.

An example of a suitable poly(ether)glycol moiety is—[O—CH₂—CHR′]_(n)—R″, wherein R′ can be H or C₁-C₃ alkyl, R″ can be H,—OH, C₁-C₆ alkyl, C₁-C₆ alkoxy, aryl, aryloxy, arylalkyl, or arylalkoxyand n can be an integer in the range of 1 to 120, preferably of 1 to 60,more preferably of 1 to 30.

In another embodiment of the invention, said second moiety M_(B) beinghydrophilic is not a PEG moiety.

In one embodiment of the invention, said second moiety M_(B) beinghydrophilic is a sulfobetaine group.

According to an embodiment, the ligand of the present invention is acopolymer of general formula (III):

-   -   wherein    -   L and R are as defined in formula (I);    -   R_(A)′ and R_(A)″ represent respectively a group comprising a        first moiety M_(A)′ and a group comprising a first moiety        M_(A)″, said moieties M_(A)′ and M_(A)″ having affinity for the        surface of a nanocrystal;    -   R_(B)′ and R_(B)″ represent respectively a group comprising a        second moiety    -   M_(B)′ and a group comprising a second moiety M_(B)″, said        moieties M_(B)′ and M_(B)″ being hydrophilic;    -   R^(1′), R^(2′), R^(3′), R^(4′), R^(5′), R^(6′), R^(1″), R^(2″),        R^(3″), R^(4″), R^(5″) and R^(6″) represent each independently H        or a group selected from the alkyl, alkenyl, aryl, hydroxyl,        halogen, alkoxy and carboxylate, amide;    -   n represents a positive integer, preferably an integer ranging        from 1 to 1000, preferably from 1 to 499, from 1 to 249 or from        1 to 99;    -   x′ and x″ represent each independently a percentage of n,        wherein at least one of x′ and x″ is different from 0% of n;        wherein x′ and x″ are different from 100% of n, preferably x′        and x″ are ranging from more than 0% to less than 100% of n,        preferably from more than 0% to 50% of n, from more than 0% to        50% of n;    -   y′ and y″ represent each independently a percentage of n,        wherein at least one of y′ and y″ is different from 0% of n;        wherein y′ and y″ are different from 100% of n, preferably y′        and y″ are from more than 0% to less than 100% of n, preferably        from more than 0% to 50% of n, from more than 0% to 50% of n;    -   wherein x′+x″+y′+y″ is equal to 100% of n.

In one embodiment, each of x′ and x″ is independently a percentage of n,preferably a percentage selected in the group of 0, 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,44, 45, 46, 47, 48, 49, 50% of n, with the condition that at least oneof x′ and x″ is not 0%.

In one embodiment, each of y′ and y″ is independently a percentage of n,preferably a percentage selected in the group of 0, 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,44, 45, 46, 47, 48, 49, 50% of n, with the condition that at least oneof y′ and y″ is not 0%.

In one embodiment of the invention, R₂′, R₃′, R₂″, R₃″, R₅′, R₆′, R₅″and R₆″ are H.

In one embodiment of the invention, R₁′, R₁″, R₄′ and R₄″ are alkylgroups, preferably methyl.

In one embodiment of the invention, said moiety M_(A) comprises saidmoieties M_(A)′ and M_(A)″. In one embodiment of the invention, saidmoiety M_(B) comprises said moieties M_(B)′ and M_(B)″.

In one embodiment of the invention, said x is equal to x′+x″. In oneembodiment of the invention, said y is equal to y′+y″.

In one embodiment of the invention, said first moieties M_(A)′ andM_(A)″ having affinity for the surface of a nanocrystal and inparticular affinity for a metal present at the surface of a nanocrystalinclude, but is not limited to, a thiol moiety, a dithiol moiety, animidazole moiety, a catechol moiety, a pyridine moiety, a pyrrolemoiety, a thiophene moiety, a thiazole moiety, a pyrazine moiety, acarboxylic acid or carboxylate moiety, a naphthyridine moiety, aphosphine moiety, a phosphine oxide moiety, a phenol moiety, a primaryamine moiety, a secondary amine moiety, a tertiary amine moiety, aquaternary amine moiety, an aromatic amine moiety, or a combinationthereof.

In one embodiment of the invention, said first moieties M_(A)′ andM_(A)″ having affinity for the surface of a nanocrystal and inparticular affinity for a material E selected in the group of O, S, Se,Te, N, P, As, and mixture thereof, include, but is not limited to, animidazole moiety, a pyridine moiety, a pyrrole moiety, a thiazolemoiety, a pyrazine moiety, a naphthyridine moiety, a phosphine moiety, aphosphine oxide moiety, a primary amine moiety, a secondary aminemoiety, a tertiary amine moiety, a quaternary amine moiety, an aromaticamine moiety, or a combination thereof.

In one embodiment of the invention, said first moiety M_(A)′ havingaffinity for the surface of a nanocrystal is a dithiol moiety and saidfirst moiety M_(A)″ having affinity for the surface of a nanocrystal isan imidazole moiety.

In one embodiment of the invention, said second moieties M_(B)′ andM_(B)″ being hydrophilic include, but is not limited to, a zwitterionicmoiety (i.e. any compound having both a negative charge and a positivecharge, preferably a group with both an ammonium group and a sulfonategroup or a group with both an ammonium group and a carboxylate group)such as for example an aminocarboxylate, an aminosulfonate, acarboxybetaine moiety wherein the ammonium group may be included in analiphatic chain, a five-membered cycle, a five-membered heterocyclecomprising 1, 2 or 3 further nitrogen atoms, a six-membered cycle, asix-membered heterocycle comprising 1, 2, 3 or 4 further nitrogen atoms,a sulfobetaine moiety wherein the ammonium group may be included in analiphatic chain, a five-membered cycle, a five-membered heterocyclecomprising 1, 2 or 3 further nitrogen atoms, a six-membered cycle, asix-membered heterocycle comprising 1, 2, 3 or 4 further nitrogen atoms,a phosphobetaine wherein the ammonium group may be included in analiphatic chain, a five-membered cycle, a five-membered heterocyclecomprising 1, 2 or 3 further nitrogen atoms, a six-membered cycle, asix-membered heterocycle comprising 1, 2, 3 or 4 further nitrogen atoms,a phosphorylcholine, a phosphocholine moiety, and combinations thereofor a PEG moiety or a poly(ether)glycol moiety, wherein if M_(B)′ is aPEG moiety, then M_(B)″ is not a PEG moiety and inversely.

In one embodiment of the invention, said second moiety M_(B)′ beinghydrophilic is a sulfobetaine group and said second moiety M_(B)″ beinghydrophilic is a PEG moiety or a poly(ether)glycol moiety.

In one embodiment, the ligand of the invention is a copolymersynthesized from at least 2 monomers, said monomers being:

-   -   one anchoring monomer A wherein M_(A) is a dithiol group,    -   one hydropohilic monomer B wherein M_(B) is a sulfobetaine        group.

In one embodiment of the invention, R_(A) comprising the first moietyM_(A) can have the formula -L_(A)-M_(A), wherein L_(A) can be a bond oran alkylene, alkenylene, or arylene linking group having 1 to 50 chainatoms and can be optionally interrupted or terminated by —O—, —S—,—NR₇—, wherein R₇ is H or alkyl, —CO—, —NHCO—, —CONH— or a combinationthereof and M_(A) corresponds to the first moiety as described hereabove.

Preferably, L_(A) is —C(═O)—NH—(CH₂)_(m)—NH—C(═O)—(CH₂)_(p)—, wherein mis an integer ranging from 1 to 20, preferably from 1 to 10, preferablyfrom 1 to 5, preferably 2, 3, 4 and p is an integer ranging from 1 to20, preferably from 1 to 10, preferably from 1 to 6, preferably 3, 4, 5.

In a preferred embodiment, -L_(A)-M_(A) is:

wherein m, p and M_(A) are as defined above, preferably m is equal to 3and p is equal to 4.

In a preferred embodiment, M_(A) is a dithiol moiety and -L_(A)-M_(A)may be represented by:

wherein m, p and M_(A) are as defined above, preferably m is equal to 3and p is equal to 4.

In a preferred embodiment, -L_(A)-M_(A) is:

wherein m, p and M_(A) are as defined above preferably m is equal to 3and p is equal to 4.

In a preferred embodiment, -L_(A)-M_(A) is:

In one embodiment of the invention, R_(B) comprising the second moietyM_(B) can have the formula -L_(B)-M_(B), wherein L_(B) can be a bond oran alkylene, alkenylene, or arylene linking group having 1 to 50 chainatoms and can be optionally interrupted or terminated by —O—, —S—,—NR₇—, wherein R₇ is H or alkyl, —CO—, —NHCO—, —CONH— or a combinationthereof and M_(B) corresponds to the second moiety as described hereabove.

Preferably, L_(B) is —C(═O)—NH—(CH₂)_(q)—, wherein q is an integerranging from 1 to 20, preferably from 1 to 10, preferably from 1 to 5,preferably 2, 3, 4.

In a preferred embodiment, -L_(B)-M_(B) is:

wherein q and M_(B) are as defined above, preferably q is equal to 3.

In a preferred embodiment, -L_(B)-M_(B) may be represented by:

wherein q is as defined above and M_(B) is a zwitterionic moiety,preferably q is equal to 3.

In one preferred embodiment, -L_(B)-M_(B) may be represented by:

wherein q is as defined above, preferably q is equal to 3

-   -   s is an integer ranging from 1 to 5, preferably s is equal 2, 3        or 4,    -   R₁₂, R₁₃, R₁₄ and R₁₅ are each independently H, or a group        selected from an alkyl, alkenyl, aryl, hydroxyle, halogen,        alkoxy, carboxylate.

In another preferred embodiment, -L_(B)-M_(B) may be represented by:

wherein q is as defined above, preferably q is equal to 3,

-   -   s is an integer ranging from 1 to 5, preferably s is equal 2, 3        or 4,    -   t is 1 or 2,    -   R₁₄ and R₁₅ are each independently H, or a group selected from        an alkyl, alkenyl, aryl, hydroxyle, halogen, alkoxy,        carboxylate,    -   X₁, X₂ and X₃ are each independently N or C,    -   the bounds represented by a dotted line being each independently        either absent or present,    -   R₁₂, R₁₆, R₁₇, R₁₈, R₁₉, R₂₀ and R₂₁ are each independently H,        or a group selected from an alkyl, alkenyl, aryl, hydroxyle,        halogen, alkoxy, carboxylate, or may be absent when the bound        represented by a dotted line is present.

In a preferred embodiment -L_(B)-M_(B) is:

wherein q is as defined above.

In a preferred embodiment -L_(B)-M_(B) is:

In a specific embodiment, the ligand of the invention is of formula(I-a):

wherein n, x, y, L, R, L_(A), M_(A), L_(B) and R_(B) are as definedabove.

In a specific embodiment, the ligand of the invention is of formula(I-b):

wherein n, x, y, L, R, m, p, M_(A), L_(B) and M_(B) are as definedabove.

In a specific embodiment, the ligand of the invention is of formula(I-c):

wherein n, x, y, L, R, q, M_(B), L_(A) and M_(A) are as defined above.

In a specific embodiment, the ligand of the invention is of formula(I-d):

wherein n, x, y, L, R, m, p, M_(A), q and M_(B) are as defined above.

In a specific embodiment, the ligand of the invention is of formula(I-e):

wherein n, x, y, L and R are as defined in formula (I) above; or areduced form thereof.

In another specific embodiment, the ligand of the invention is offormula (I-f):

wherein n, x, y and L are as defined in formula (I) above; or a reducedform thereof.

In one embodiment of the invention, the ligand has a molecular weightfrom about 1,000 g/mol to about 200,000 g/mol, preferably from about1,000 g/mol to about 100,000 g/mol, preferably from about 1,000 g/mol toabout 50,000 g/mol, from about 2,000 g/mol to 50,000 g/mol, morepreferably from about 2,000 g/mol to about 10,000 g/mol, from about2,000 g/mol to 10,000 g/mol.

In one embodiment of the invention, the ligand has a polydispersityindex inferior to 10, preferably inferior to 9, 8, 7, 6, 5, 4, 3, 2, 1.

In one embodiment of the invention, the ligand has a ratio of monomersA/B in number from about 1/99 to about 99/1. In a particular embodiment,the ligand has a ratio of monomers A/B in number from about 1/99 toabout 50/50, preferably from about 3/97 to about 40/60, more preferablyfrom about 10/90 to about 50/50. In another particular embodiment, theligand has a ratio of monomers A/B in number from about 50/50 to about99/1, preferably from about 40/60 to about 90/10. In another embodiment,the ligand has a ratio of monomers A/B in number from about 1/99 toabout 75/25, preferably from about 5/95 to about 50/50, more preferablyfrom about 5/95 to about 25/75. In a specific embodiment, the ligand hasa ratio of monomers A/B in number of about 50/50. In a specificembodiment, the ligand has a ratio of monomers A/B in number of about20/80.

According to one embodiment, the synthesis of the ligand may beperformed in presence of monomer A and monomer B with a ratio of molaramounts of A to B ranging from 1/99 to 99/1, preferably from 5/95 to50/50, preferably from 10/90 to 50/50; preferably from 10/90 to 30/70,more preferably 20/80.

In another embodiment, of the invention, the ligand is a copolymersynthesized from at least 3 monomers, said monomers being:

-   -   one anchoring monomer A as defined above,    -   one hydrophilic monomer B as defined above,    -   one hydrophobic monomer C having a side-chain comprising a        hydrophobic function M_(C),        and wherein one end of copolymer is H and the other end        comprises a functional group or a bioactive group.

According to an embodiment, the ligand of the present invention is acopolymer of general formula (IV):

H—P[(A)_(x)-co-(B)_(y)-co-(C)_(z)]_(n)-L-R

-   -   wherein    -   A, B, L, R and n are as defined above;    -   C represents an hydrophobic monomer having a side-chain        comprising a moiety M_(C) being hydrophobic;    -   x, y and z represent each independently a percentage of n,        wherein x and y are different from 0% of n and different from        100% of n, preferably x, y and z are ranging from more than 0%        to less than 100% of n, preferably from more than 0% to 80% of        n, from more than 0% to 50% of n and wherein x+y+z is equal to        100% of n.

According to an embodiment, the ligand of the present invention is acopolymer of general formula (V):

-   -   wherein    -   n, L, R, R_(A), R_(B), R¹, R², R³, R⁴, R⁵ and R⁶ are as defined        above;    -   R_(C) represents a group comprising the third moiety M_(C) being        hydrophobic;    -   R⁸, R⁹, and R¹⁰ represent each independently H or a group        selected from the alkyl, alkenyl, aryl, hydroxyl, halogen,        alkoxy and carboxylate, amide;    -   x, y and z represent each independently a percentage of n,        wherein x and y are different from 0% of n and different from        100% of n, preferably x, y and z are ranging from more than 0%        to less than 100% of n, preferably from more than 0% to 80% of        n, from more than 0% to 50% of n; and wherein x+y+z is equal to        100% of n.

In one embodiment of the invention, R², R³, R⁵, R⁶, R⁹, and R¹⁰ are H.

In one embodiment, R¹, R⁴, and R⁸ are alkyl groups, preferably methyl.

According to one embodiment, said third moiety M_(C) being hydrophobicincludes, but is not limited to, alkyl, aryl, alkylaryl, arylalkyl,alkenyl groups.

According to one embodiment, preferred monomers C are those described inthe following table:

Compound n° Name C-1 N-hexylmethacrylamide C-2 N-heptylmethacrylamideC-3 N-octylmethacrylamide C-4 N-nonylmethacrylamide C-5N-decylmethacrylamide C-6 N-hexylacrylamide C-7 N-heptylacrylamide C-8N-octylacrylamide C-9 N-nonylacrylamide C-10 N-decylacrylamide C-11N-(2-(1H-imidazol-1-yl)ethyl)methacrylamide C-12N-(2-(1H-imidazol-1-yl)ethyl)acrylamide C-13N-(2-(4H-imidazol-4-yl)ethyl)methacrylamide C-14N-(2-(4H-imidazol-4-yl)ethyl)acrylamide C-15 N-phenylmethacrylamide C-16N-benzylmethacrylamide C-17 N-isopropylmethacrylamide C-18N-isobutylmethacrylamide C-19 N-phenylacrylamide C-20 N-benzylacrylamideC-21 N-isopropylacrylamide C-22 N-isobutylacrylamide C-23N-hexylmethacrylate C-24 N-heptylmethacrylate C-25 N-octylmethacrylateC-26 N-nonylmethacrylate C-27 N-decylmethacrylate C-28 N-hexylacrylateC-29 N-heptylacrylate C-30 N-octylacrylate C-31 N-nonylacrylate C-32N-decylacrylate C-33 N-(2-(1H-imidazol-1-yl)ethyl)methacrylate C-34N-(2-(1H-imidazol-1-yl)ethyl)acrylate C-35N-(2-(4H-imidazol-4-yl)ethyl)methacrylate C-36N-(2-(4H-imidazol-4-yl)ethyl)acrylate C-37 N-phenylmethacrylate C-38N-benzylmethacrylate C-39 N-isopropylmethacrylate C-40N-isobutylmethacrylate C-41 N-phenylacrylate C-42 N-benzylacrylate C-43N-isopropylacrylate C-44 N-isobutylacrylate

In one embodiment of the invention, R_(C) comprising the third moietyM_(C) can have the formula -L_(C)-M_(C), wherein L_(C) can be a bond oran alkylene, alkenylene or arylene linking group having 1 to 8 chainatoms.

In one embodiment of the invention, said first moiety M_(A) is not adihydrolipoic acid (DHLA) moiety.

In another embodiment of the invention, said first moiety M_(A) is notan imidazole moiety.

In one embodiment, when B comprises a monomer comprising a second moietyM_(B) which is a PEG moiety, then B further comprises at least onemonomer comprising a second moiety M_(B) which is not a PEG moiety.

In one embodiment of the invention, when the first moiety M_(A) is animidazole moiety, the second moiety M_(B) is not a PEG moiety.

In one embodiment of the invention, when the first moiety M_(A) is animidazole moiety, the second moiety M_(B) is not a sulfobetaine moiety.In a specific embodiment of the invention, when the first moiety M_(A)is an imidazole moiety, the second moiety M_(B) is not—N⁺(Me)₂-(CH₂)₂—SO₃ ⁻ or —N⁺(Me)₂-(CH₂)₃—SO₃ ⁻.

In one embodiment of the invention, when the first moiety M_(A) is animidazole moiety, the second moiety M_(B) is not a carboxybetainemoiety. In a specific embodiment of the invention, when the first moietyM_(A) is an imidazole moiety, the second moiety M_(B) is not—N⁺(Me)₂-(CH₂)₂—COO⁻.

In one embodiment of the invention, when the first moiety M_(A) is animidazole moiety, the second moiety M_(B) is not a phosphobetainemoiety. In a specific embodiment of the invention, when the first moietyM_(A) is an imidazole moiety, the second moiety M_(B) is not —O—P(O₂⁻)—P—(CH₂)₂—N⁺(Me)₃.

In one embodiment of the invention, when the first moiety M_(A) is adithiol group, and B comprises a monomer comprising a second moietyM_(B)′ which is a PEG moiety, then B further comprises at least onemonomer comprising a second moiety M_(B)″ which is not a PEG moiety.

According to one embodiment, preferred combinations of monomers A and Bare described in the following table:

N° A B 1 5(1,2-dithiolan-3-yl)- 3-((3- N-(3-methacryl-methacrylamidopropyl)dimethylammonio) amidopro- propane-1-sulfonatepyl)pentanamide 2 6-(1,2-dithiolan- 3-((3- 3-yl)-N-(3-methacrylamidopropyl)dimethylammonio) methacrylamido-propane-1-sulfonate propyl)hexanamide 3 7-(1,2-dithiolan- 3-((3-3-yl)-N-(3- methacrylamidopropyl)dimethylammonio) methacrylamido-propane-1-sulfonate propyl)heptanamide 4 8-(1,2-dithiolan- 3-((3-3-yl)-N-(3- methacrylamidopropyl)dimethylammonio) methacrylamido-propane-1-sulfonate propyl)octanamide 5 9-(1,2-dithiolan- 3-((3-3-yl)-N-(3- methacrylamidopropyl)dimethylammonio) methacrylamido-propane-1-sulfonate propyl)nonanamide 6 10-(1,2-dithiolan- 3-((3-3-yl)-N-(3- methacrylamidopropyl)dimethylammonio) methacrylamido-propane-1-sulfonate propyl)decanamide 7 5-(1,2-dithiolan- 3-((3-3-yl)-N-(3-acryl- methacrylamidopropyl)dimethylammonio) amidopropyl)pen-propane-1-sulfonate tanamide 8 6-(1,2-dithiolan- 3-((3- 3-yl)-N-(3-methacrylamidopropyl)dimethylammonio) acrylamidopro- propane-1-sulfonatepyl)hexanamide 9 7-(1,2-dithiolan- 3-((3- 3-yl)-N-(3-acryl-methacrylamidopropyl)dimethylammonio) amidopropyl)hepta-propane-1-sulfonate namide 10 8-(1,2-dithiolan- 3-((3- 3-yl)-N-(3-acryl-methacrylamidopropyl)dimethylammonio) amidopropyl)octa-propane-1-sulfonate namide 11 9-(1,2-dithiolan- 3-((3- 3-yl)-N-(3-acryl-methacrylamidopropyl)dimethylammonio) amidopropyl)nona-propane-1-sulfonate namide 12 10-(1,2-dithiolan- 3-((3-3-yl)-N-(3-acryl- methacrylamidopropyl)dimethylammonio)amidopropyl)deca- propane-1-sulfonate namide 13 3-(5-(1,2-dithiolan-3-3-((3- yl)pentanamido)propyl methacrylamidopropyl)dimethylammonio)methacrylate propane-1-sulfonate 14 3-(6-(1,2-dithiolan-3- 3-((3-yl)hexanamido)propyl methacrylamidopropyl)dimethylammonio) methacrylatepropane-1-sulfonate 15 3-(7-(1,2-dithiolan-3- 3-((3-yl)heptanamido)propyl methacrylamidopropyl)dimethylammonio) methacrylatepropane-1-sulfonate 16 3-(8-(1,2-dithiolan-3- 3-((3-yl)octanamido)propyl methacrylamidopropyl)dimethylammonio) methacrylatepropane-1-sulfonate 17 3-(9-(1,2-dithiolan-3- 3-((3-yl)nonanamido)propyl methacrylamidopropyl)dimethylammonio) methacrylatepropane-1-sulfonate 18 3-(10-(1,2- 3-((3- dithiolan-3-methacrylamidopropyl)dimethylammonio) yl)decanamido)propylpropane-1-sulfonate methacrylate 19 3-(5-(1,2-dithiolan-3- 3-((3-yl)pentanamido)propyl methacrylamidopropyl)dimethylammonio) acrylatepropane-1-sulfonate 20 3-(6-(1,2-dithiolan-3- 3-((3-yl)hexanamido)propyl methacrylamidopropyl)dimethylammonio) acrylatepropane-1-sulfonate 21 3-(7-(1,2-dithiolan-3- 3-((3- ylheptamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 223-(8-(1,2-dithiolan-3- 3-((3- yl)octanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 233-(9-(1,2-dithiolan-3- 3-((3- yl)nonanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 243-(10-(1,2- 3-((3- dithiolan-3- methacrylamidopropyl)dimethylammonio)yl)decanamido)propyl propane-1-sulfonate acrylate 25 5-mercapto-N-(3-3-((3- methacrylamido- methacrylamidopropyl)dimethylammonio)propyl)pentanamide propane-1-sulfonate 26 6-mercapto-N-(3- 3-((3-methacrylamido- methacrylamidopropyl)dimethylammonio) propyl)hexanamidepropane-1-sulfonate 27 7-mercapto-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)heptanamidepropane-1-sulfonate 28 8-mercapto-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)octanamidepropane-1-sulfonate 29 9-mercapto-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)nonanamidepropane-1-sulfonate 30 10-mercapto-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)decanamidepropane-1-sulfonate 31 N-(3-acryl 3-((3- amidopropyl)-5-methacrylamidopropyl)dimethylammonio) mercaptopentanamidepropane-1-sulfonate 32 N-(3-acryl- 3-((3- amidopropyl)-6-methacrylamidopropyl)dimethylammonio) mercaptohexanamidepropane-1-sulfonate 33 N-(3-acryl- 3-((3- amidopropyl)-7-methacrylamidopropyl)dimethylammonio) mercaptoheptanamidepropane-1-sulfonate 34 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 8-mercaptooctanamidepropane-1-sulfonate 35 N-(3-acryl- 3-((3- amidopropyl)-9-methacrylamidopropyl)dimethylammonio) mercaptononanamidepropane-1-sulfonate 36 N-(3-acryl- 3-((3- amidopropyl)-10-methacrylamidopropyl)dimethylammonio) mercaptodecanamidepropane-1-sulfonate 37 3-(5-mercapto- 3-((3- pentanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate38 3-(6-mercapto- 3-((3- hexanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate39 3-(7-mercapto- 3-((3- heptanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate40 3-(8-mercapto- 3-((3- octanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate41 3-(9-mercapto- 3-((3- nonanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate42 3-(10-mercapto- 3-((3- decanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate43 3-(5-mercapto- 3-((3- pentanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 443-(6-mercapto- 3-((3- hexanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 453-(7-mercapto- 3-((3- heptanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 463-(8-mercapto- 3-((3- octanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 473-(9-mercapto- 3-((3- nonanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 483-(10-mercapto- 3-((3- decanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 495-((3-methacryl- 3-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 5-oxopentanoic acidpropane-1-sulfonate 50 6-((3-methacry- 3-((3- lamidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 6-oxohexanoic acidpropane-1-sulfonate 51 7-((3-methacryl- 3-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 7-oxoheptanoic acidpropane-1-sulfonate 52 8-((3-methacryl- 3-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 8-oxooctanoic acidpropane-1-sulfonate 53 9-((3-methacryl- 3-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 9-oxononanoic acidpropane-1-sulfonate 54 10-((3-methacryl- 3-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 10-oxodecanoic acidpropane-1-sulfonate 55 5-((3-acrylamido- 3-((3- propyl)amino)-5-methacrylamidopropyl)dimethylammonio) oxopentanoic acidpropane-1-sulfonate 56 6-((3-acrylamido- 3-((3- propyl)amino)-6-methacrylamidopropyl)dimethylammonio) oxohexanoic acidpropane-1-sulfonate 57 7-((3-acrylamido- 3-((3- propyl)amino)-7-methacrylamidopropyl)dimethylammonio) oxoheptanoic acidpropane-1-sulfonate 58 8-((3-acrylamido- 3-((3- propyl)amino)-8-methacrylamidopropyl)dimethylammonio) oxooctanoic acidpropane-1-sulfonate 59 9-((3-acrylamido- 3-((3- propyl)amino)-9-methacrylamidopropyl)dimethylammonio) oxononanoic acidpropane-1-sulfonate 60 10-((3-acryl- 3-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 10-oxodecanoic acidpropane-1-sulfonate 61 5-((3-(metha- 3-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- propane-1-sulfonate5-oxopentanoic acid 62 6-((3-(metha- 3-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- propane-1-sulfonate6-oxohexanoic acid 63 7-((3-(metha- 3-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- propane-1-sulfonate7-oxoheptanoic acid 64 8-((3-(metha- 3-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- propane-1-sulfonate8-oxooctanoic acid 65 9-((3-(metha- 3-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- propane-1-sulfonate9-oxononanoic acid 66 10-((3-(metha- 3-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- propane-1-sulfonate10-oxodecanoic acid 67 5-((3- 3-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-5- propane-1-sulfonateoxopentanoic acid 68 6-((3- 3-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-6- propane-1-sulfonateoxohexanoic acid 69 7-((3- 3-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-7- propane-1-sulfonateoxoheptanoic acid 70 8-((3- 3-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-8- propane-1-sulfonateoxooctanoic acid 71 9-((3- 3-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-9- propane-1-sulfonateoxononanoic acid 72 10-((3- 3-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-10- propane-1-sulfonateoxodecanoic acid 73 5-amino-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)pentanamidepropane-1-sulfonate 74 6-amino-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)hexanamidepropane-1-sulfonate 75 7-amino-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)heptanamidepropane-1-sulfonate 76 8-amino-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)octanamidepropane-1-sulfonate 77 9-amino-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)nonanamidepropane-1-sulfonate 78 10-amino-N-(3- 3-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)decanamidepropane-1-sulfonate 79 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 5-aminopentanamidepropane-1-sulfonate 80 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 6-aminohexanamidepropane-1-sulfonate 81 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 7-aminheptanamidepropane-1-sulfonate 82 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 8-aminooctanamidepropane-1-sulfonate 83 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 9-aminononanamidepropane-1-sulfonate 84 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 10-aminodecanamidepropane-1-sulfonate 85 3-(5-aminopenta- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate86 3-(6-aminohexa- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate87 3-(7-aminohepta- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate88 3-(8-aminoocta- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate89 3-(9-amino- 3-((3- nonamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate90 3-(10-aminodeca- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate91 3-(5-aminopenta- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 923-(6-aminohexa- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 933-(7-aminohepta- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 943-(8-aminoocta- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 953-(9-amino- 3-((3- nonamido)propyl methacrylamidopropyl)dimethylammonio)acrylate propane-1-sulfonate 96 3-(10-aminodeca- 3-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 975-(1H-imidazol- 3-((3- 1-yl)-N-(3- methacrylamidopropyl)dimethylammonio)methacrylamido- propane-1-sulfonate propyl)pentanamide 986-(1H-imidazol- 3-((3- 1-yl)-N-(3- methacrylamidopropyl)dimethylammonio)methacrylamido- propane-1-sulfonate propyl)hexanamide 997-(1H-imidazol-1-yl)- 3-((3- N-(3-methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)heptanamidepropane-1-sulfonate 100 8-(1H-imidazol-1-yl)- 3-((3-N-(3-methacrylamido- methacrylamidopropyl)dimethylammonio)propyl)octanamide propane-1-sulfonate 101 9-(1H-imidazol-1-yl)- 3-((3-N-(3-methacrylamido- methacrylamidopropyl)dimethylammonio)propyl)nonanamide propane-1-sulfonate 102 10-(1H- 3-((3- imidazol-1-yl)-methacrylamidopropyl)dimethylammonio) N-(3-methacrylamido-propane-1-sulfonate propyl)decanamide 103 N-(3-acryl- 3-((3-amidopropyl)- methacrylamidopropyl)dimethylammonio) 5-(1H-imidazol-propane-1-sulfonate 1-yl)pentanamide 104 N-(3-acryl- 3-((3-amidopropyl)- methacrylamidopropyl)dimethylammonio) 6-(1H-imidazol-propane-1-sulfonate 1-yl)hexanamide 105 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 7-(1H-imidazol-propane-1-sulfonate 1-yl)hepanamide 106 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 8-(1H-imidazol-propane-1-sulfonate 1-yl)octanamide 107 N-(3-acryl- 3-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 9-(1H-imidazol-propane-1-sulfonate 1-yl)nonanamide 108 N-(3-acrylamido- 3-((3-propyl)-10-(1H- methacrylamidopropyl)dimethylammonio) imidazol-1-propane-1-sulfonate yl)decanamide 109 3-(5-(1H-imidazol-1- 3-((3-yl)pentanamido)propyl methacrylamidopropyl)dimethylammonio) methacrylatepropane-1-sulfonate 110 3-(6-(1H-imidazol-1- 3-((3- yl)hexanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate111 3-(7-(1H-imidazol-1- 3-((3- yl)heptanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate112 3-(8-(1H-imidazol-1- 3-((3- yl)octanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate113 3-(9-(1H-imidazol-1- 3-((3- yl)nonanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate114 3-(10-(1H-imidazol-1- 3-((3- yl)decanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate propane-1-sulfonate115 3-(5-(1H-imidazol-1- 3-((3- yl)pentanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 1163-(6-(1H-imidazol-1- 3-((3- yl)hexanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 1173-(7-(1H-imidazol-1- 3-((3- yl)heptanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 1183-(8-(1H-imidazol-1- 3-((3- yl)octanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 1193-(9-(1H-imidazol-1- 3-((3- yl)nonanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 1203-(10-(1H-imidazol-1- 3-((3- yl)decanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate propane-1-sulfonate 1215-(1,2-dithiolan-3-yl)- 4-((3- N-(3-methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)pentanamide butanoate 1226-(1,2-dithiolan-3-yl)- 4-((3- N-(3-methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)hexanamide butanoate 1237-(1,2-dithiolan-3-yl)- 4-((3- N-(3-methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)heptanamide butanoate 1248-(1,2-dithiolan-3-yl)- 4-((3- N-(3-methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)octanamide butanoate 1259-(1,2-dithiolan-3-yl)- 4-((3- N-(3-methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)nonanamide butanoate 12610-(1,2- 4-((3- dithiolan-3-yl)- methacrylamidopropyl)dimethylammonio)N-(3-methacrylamido- butanoate propyl)decanamide 1275-(1,2-dithiolan-3-yl)- 4-((3- N-(3-acrylamidopro-methacrylamidopropyl)dimethylammonio) pyl)pentanamide butanoate 1286-(1,2-dithiolan-3-yl)- 4-((3- N-(3-acrylamidopro-methacrylamidopropyl)dimethylammonio) pyl)hexanamide butanoate 1297-(1,2-dithiolan-3-yl)- 4-((3- N-(3-acrylamidopro-methacrylamidopropyl)dimethylammonio) pyl)heptanamide butanoate 1308-(1,2-dithiolan-3-yl)- 4-((3- N-(3-acrylamidopro-methacrylamidopropyl)dimethylammonio) pyl)octanamide butanoate 1319-(1,2-dithiolan-3-yl)- 4-((3- N-(3-acrylamidopro-methacrylamidopropyl)dimethylammonio) pyl)nonanamide butanoate 13210-(1,2- 4-((3- dithiolan-3-yl)- methacrylamidopropyl)dimethylammonio)N-(3-acrylamidopro- butanoate pyl)decanamide 133 3-(5-(1,2-dithiolan-3-4-((3- yl)pentanamido)propyl methacrylamidopropyl)dimethylammonio)methacrylate butanoate 134 3-(5-(1,2-dithiolan-3- 4-((3-yl)hexanamido)propyl methacrylamidopropyl)dimethylammonio) methacrylatebutanoate 135 3-(5-(1,2-dithiolan-3- 4-((3- yl)heptanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1363-(5-(1,2-dithiolan-3- 4-((3- yl)octanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1373-(5-(1,2-dithiolan-3- 4-((3- yl)nonanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1383-(5-(1,2-dithiolan-3- 4-((3- yl)decanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1393-(5-(1,2-dithiolan-3- 4-((3- yl)pentanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1403-(5-(1,2-dithiolan-3- 4-((3- yl)hexanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1413-(5-(1,2-dithiolan-3- 4-((3- ylheptamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1423-(5-(1,2-dithiolan-3- 4-((3- yl)octanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1433-(5-(1,2-dithiolan-3- 4-((3- yl)nonanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1443-(5-(1,2-dithiolan-3- 4-((3- yl)decanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1455-mercapto-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)pentanamide butanoate 1466-mercapto-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)hexanamide butanoate 1477-mercapto-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)heptanamide butanoate 1488-mercapto-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)octanamide butanoate 1499-mercapto-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)nonanamide butanoate 15010-mercapto-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)decanamide butanoate 151N-(3-acryl- 4-((3- amidopropyl)- methacrylamidopropyl)dimethylammonio)5-mercapto- butanoate pentanamide 152 N-(3-acryl- 4-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 6-mercapto- butanoate hexanamide153 N-(3-acryl- 4-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 7-mercapto- butanoate heptanamide154 N-(3-acryl 4-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 8-mercapto- butanoate octanamide155 N-(3-acryl- 4-((3- amidopropyl)-methacrylamidopropyl)dimethylammonio) 9-mercapto- butanoate nonanamide156 N-(3-acrylamido- 4-((3- propyl)-10-methacrylamidopropyl)dimethylammonio) mercaptodecanamide butanoate 1573-(5-mercapto- 4-((3- pentanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1583-(6-mercapto 4-((3- hexanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1593-(7-mercapto- 4-((3- heptanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1603-(8-mercapto- 4-((3- octanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1613-(9-mercapto- 4-((3- nonanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1623-(10-mercapto- 4-((3- decanamido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 1633-(5-mercapto- 4-((3- pentanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1643-(6-mercapto- 4-((3- hexanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1653-(7-mercapto- 4-((3- heptanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1663-(8-mercapto- 4-((3- octanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1673-(9-mercapto- 4-((3- nonanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1683-(10-mercapto- 4-((3- decanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 1695-((3-methacryl- 4-((3- amido- methacrylamidopropyl)dimethylammonio)propyl)amino)-5- butanoate oxopentanoic acid 170 6-((3-methacryl- 4-((3-amido- methacrylamidopropyl)dimethylammonio) propyl)amino)-6- butanoateoxohexanoic acid 171 7-((3-methacryl- 4-((3- amido-methacrylamidopropyl)dimethylammonio) propyl)amino)-7- butanoateoxoheptanoic acid 172 8-((3-methacryl- 4-((3- amido-methacrylamidopropyl)dimethylammonio) propyl)amino)-8- butanoateoxooctanoic acid 173 9-((3-methacryl- 4-((3- amido-methacrylamidopropyl)dimethylammonio) propyl)amino)-9- butanoateoxononanoic acid 174 10-((3-methacryl- 4-((3- amidopropyl)amino)-methacrylamidopropyl)dimethylammonio) 10-oxodecanoic acid butanoate 1755-((3-acrylamido- 4-((3- propyl)amino)-5-methacrylamidopropyl)dimethylammonio) oxopentanoic acid butanoate 1766-((3-acrylamido- 4-((3- propyl)amino)-6-methacrylamidopropyl)dimethylammonio) oxohexanoic acid butanoate 1777-((3-acrylamido- 4-((3- propyl)amino)-7-methacrylamidopropyl)dimethylammonio) oxoheptanoic acid butanoate 1788-((3-acrylamido- 4-((3- propyl)amino)-8-methacrylamidopropyl)dimethylammonio) oxooctanoic acid butanoate 1799-((3-acrylamido- 4-((3- propyl)amino)-9-methacrylamidopropyl)dimethylammonio) oxononanoic acid butanoate 18010-((3-acrylamido- 4-((3- propyl)amino)-10-methacrylamidopropyl)dimethylammonio) oxodecanoic acid butanoate 1815-((3-(metha- 4-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- butanoate5-oxopentanoic acid 182 6-((3-(metha- 4-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- butanoate6-oxohexanoic acid 183 7-((3-(metha- 4-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- butanoate7-oxoheptanoic acid 184 8-((3-(metha- 4-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- butanoate8-oxooctanoic acid 185 9-((3-(metha- 4-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- butanoate9-oxononanoic acid 186 10-((3-(metha- 4-((3- cryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)- butanoate10-oxodecanoic acid 187 5-((3- 4-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-5- butanoateoxopentanoic acid 188 6-((3- 4-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-6- butanoateoxohexanoic acid 189 7-((3- 4-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-7- butanoateoxoheptanoic acid 190 8-((3- 4-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-8- butanoateoxooctanoic acid 191 9-((3- 4-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-9- butanoateoxononanoic acid 192 10-((3- 4-((3- (acryloyloxy)pro-methacrylamidopropyl)dimethylammonio) pyl)amino)-10- butanoateoxodecanoic acid 193 5-amino-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)pentanamide butanoate 1946-amino-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)hexanamide butanoate 1957-amino-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)heptanamide butanoate 1968-amino-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)octanamide butanoate 1979-amino-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)nonanamide butanoate 19810-amino-N-(3- 4-((3- methacrylamido-methacrylamidopropyl)dimethylammonio) propyl)decanamide butanoate 199N-(3- 4-((3- acrylamidopropyl)- methacrylamidopropyl)dimethylammonio)5-aminopentanamide butanoate 200 N-(3- 4-((3- acrylamidopropyl)-methacrylamidopropyl)dimethylammonio) 6-aminohexanamide butanoate 201N-(3- 4-((3- acrylamidopropyl)- methacrylamidopropyl)dimethylammonio)7-aminheptanamide butanoate 202 N-(3- 4-((3- acrylamidopropyl)-methacrylamidopropyl)dimethylammonio) 8-aminooctanamide butanoate 203N-(3- 4-((3- acrylamidopropyl)- methacrylamidopropyl)dimethylammonio)9-aminononanamide butanoate 204 N-(3-acrylamido- 4-((3- propyl)-10-methacrylamidopropyl)dimethylammonio) aminodecanamide butanoate 2053-(5-aminopenta- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 2063-(6-aminohexa- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 2073-(7-aminohepta- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 2083-(8-aminoocta- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 2093-(9-amino- 4-((3- nonamido)propyl methacrylamidopropyl)dimethylammonio)methacrylate butanoate 210 3-(10-aminodeca- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) methacrylate butanoate 2113-(5-aminopenta- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 2123-(6-aminohexa- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 2133-(7-aminohepta- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 2143-(8-aminoocta- 4-((3- namido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate 215 3-(9-amino-4-((3- nonamido)propyl methacrylamidopropyl)dimethylammonio) acrylatebutanoate 216 3-(10-amino- 4-((3- decanamido)propylmethacrylamidopropyl)dimethylammonio) acrylate butanoate

According to one embodiment, preferred ligands comprise combinations ofmonomers A and B as described in the table above and -L-R is—S—(CH₂)₂—(O—CH₂—CH₂)₈—COOH, —S—(CH₂)₁₂—COOH or any -L-R describedhereabove.

The present invention further relates to a method of manufacturing ofthe ligand of the invention.

In one embodiment, the manufacturing process of the ligand of theinvention comprises polymerizing an anchoring monomer A and ahydrophilic monomer B in presence of an initiator and a chain transferagent (CTA).

According to one embodiment, the synthesis of the ligand may beperformed by any radical polymerization known by those skilled in theart. According to one embodiment, the synthesis of the ligand may beperformed by controlled radical polymerization such as RAFTpolymerization (Reversible Addition-Fragmentation chain Transfer), ATRP(Atom Transfer Radical Polymerization), NMP (Nitroxide MediatedPolymerization) or iodine transfer polymerization. According to anotherembodiment, the synthesis of the ligand may be performed bynon-controlled radical polymerization.

According to one embodiment, the synthesis of the ligand may beperformed in presence of a monomer A and monomer B and a solvent such asfor example acetic acid, THF, water or a mixture thereof.

In a preferred embodiment, the solvent is acetic acid.

In one embodiment, the polymerization is performed at a temperatureranging from 40° C. to 100° C., preferably from 50° C. to 70° C., morepreferably at about 60° C.

In an embodiment, the polymerization is performed for a period of timeranging from 0.5 to 24 hours, preferably from 12 to 18 hours.

In one embodiment, the polymerization of monomers A and B is initiatedby an initiator such as for example a diazoinitiator, preferablyazobisisobutyronitrile (AIBN), 2,2′-azobis(2-methylpropionamidine); aperoxide, preferably acyl peroxides, acetyl peroxides, benzoylperoxides, alkyl peroxides, hydroperoxides, acyl alkylsulfonylperoxides, dialkyl peroxydicarbonates, diperoxyketals, ketone peroxides;a perester; an azo; a disulfide; a tetrazene; a persulfate compounds.Alternatively, the polymerization of monomers A and B is initiated by aredox reaction.

In one embodiment, the polymerization of monomers A and B is performedin presence of a chain transfer agent (CTA) comprising a moiety -L-R,wherein L and R are as defined above. In one embodiment, the chaintransfer agent (CTA) does not comprise a moiety -L-R which is—S—(CH₂)₂—COOH.

In one embodiment, the polymerization of monomers A and B is performedin presence of a chain transfer agent (CTA), wherein the CTA is asubstituted alkylthiol or a disulfide. Preferably, the alkylthiol or thedisulfide is substituted by a group selected from COOH, NH₂, PEG, DNA,RNA, PNA, polysaccharide, peptide or any functional group or anybioactive group as defined herein.

In one embodiment, the chain transfer agent (CTA) is not3-mercaptopropionic acid (MPA).

In one embodiment, the chain transfer agent (CTA) is not a RAFT agent;preferably is not a chain transfer agent selected from trithiocarbonate,dithiocarbamate or dithiobenzoate.

In one embodiment, the chain transfer agent (CTA) is not dibenzylcarbonotrithioate.

In one embodiment, the molar quantity of the initiator is ranging from0.1 to 15%, preferably from 0.1% to 10%, in moles relative to the molaramount of monomers.

In one embodiment, the molar quantity of the chain transfer agent isdifferent from 0 and is ranging up to 50%, preferably up to 20%. oneembodiment, the molar quantity of the chain transfer agent is rangingfrom 10⁻⁶% to 20%, from 10⁻⁵% to 20%, from 10⁻⁴% to 20%, from 10⁻³% to20%, from 10⁻²% to 20%, from 0.1 to 15%, from 1% to 15%, from 2% to 15%,from 5% to 15% in moles relative to the molar amount of monomers. Inanother embodiment, the molar quantity of the chain transfer agent is10% in moles relative to the molar amount of monomers. In anotherembodiment, the molar quantity of the chain transfer agent is 5% inmoles relative to the molar amount of monomers.

The invention further relates to a functionalizable or functionalizedmaterial. According to one embodiment, the invention relates to amono-functionalizable or mono-functionalized material. According toanother embodiment, the invention relates to a bi-functionalizable orbi-functionalized material.

In an embodiment, the functionalizable/functionalized material of theinvention comprises a material and at least one ligand according to theinvention. In one embodiment, the material is selected from the groupcomprising metals, semiconductors, oxides, lanthanides or mixturesthereof. In one embodiment, the material is preferably selected fromgold, iron, silver, copper, aluminum, platinum, lead, palladium, ironoxide, titanium dioxide, cerium oxide, metal chalcogenide, metalpnictide, cadmium, zinc, magnesium, mercury, gallium, indium, thallium,cobalt, tin or mixtures thereof.

In a specific embodiment, the material is under the form of particles.In one embodiment, the particles of the invention have the shape of asphere, a cube, a tetrahedron, a rod, a wire, a platelet, a tube, acube, a ribbon, or mixture thereof. According to an embodiment,particles are microparticles or nanoparticles, preferably nanoparticles.According to one embodiment, microparticles are microspheres. Accordingto one embodiment, nanoparticles are nanocrystals, preferably under theform of quantum dots.

An object of the invention is thus a nanomaterial comprising ananocrystal complexed with at least one ligand of the invention.

In one embodiment, said nanocrystal is a 0D, 1D, or 2D nanocrystal.

In one embodiment, said nanocrystal may be for instance a nanosheet, ananorod, a nanoplatelet, a nanoplate, a nanoprism, a nanowall, ananodisk, a nanoparticle, a nanowire, a nanopowder, a nanotube, ananotetrapod, a nanoribbon, a nanobelt, a nanoneedle, a nanocube, ananoball, a nanocoil, a nanocone, a nanopiller, a nanoflower, or aquantum dot.

In one embodiment, said nanocrystal is inorganic. In another embodiment,said nanocrystal is organic.

In one embodiment, said nanocrystal is a semiconductor material, aceramic material, a magnetic material or a metallic material.

In one embodiment, said nanocrystal is a semi-conductor selected fromgroup IV, group IIIA-VA, group IIA-VIA, group IIIA-VIA, groupIA-IIIA-VIA, group IIA-VA, group WA-VIA, group VIB-VIA, group VB-VIA, orgroup IVB-VIA.

In one embodiment, said nanocrystal is a material MxEy, wherein:

-   -   M is Zn, Cd, Hg, Cu, Ag, Al, Ga, In, Si, Ge, Pb, Sb, Pd, Fe, Au,        Ti, Bi, W, Mo, V or a mixture thereof,    -   E is O, S, Se, Te, N, P, As, or a mixture thereof, and    -   x and y are independently a decimal number from 0 to 5, at the        condition that when x is 0, y is not 0 and inversely.

In one embodiment, said material MxEy comprises cationic elements M andanionic elements E in stoichiometric ratio, said stoichiometric ratiobeing characterized by values of x and y corresponding to absolutevalues of mean oxidation number of elements E and M respectively.

In one embodiment, said nanocrystal is a material selected from Si, Ge,CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, PbS, PbSe, PbTe,CuInS₂, CuInSe₂, AgInS₂, AgInSe₂, CuS, Cu₂S, Ag₂S, Ag₂Se, Ag₂Te, InN,InP, InAs, InSb, In₂5₃, Cd₃P₂, Zn₃P₂, Cd₃As₂, Zn₃As₂, ZnO, AN, AlP,AlAs, AlSb, GaN, GaP, GaAs, GaSb, FeS₂, TiO₂, Bi₂S₃, Bi₂Se₃, Bi₂Te₃,MoS₂, WS₂, VO₂, and alloys and mixtures thereof.

In one embodiment, said nanocrystal is a metallic material such as gold,silver, copper, aluminum, iron, platinum, lead, palladium, iron oxide,titanium dioxide, cerium oxide, metal chalcogenide, metal pnictide,cadmium, zinc, magnesium, mercury, gallium, indium, thallium, cobalt,tin or mixtures thereof.

In one embodiment, said nanocrystal presents a heterostructure, whichmeans that the nanocrystal of the invention is partially coated by atleast one layer of inorganic material.

A semiconductor nanocrystal is capable of emitting electromagneticradiation upon excitation (i.e., the semiconductor nanocrystal isluminescent) and includes a “core” of one or more first semiconductormaterials, and may be surrounded by a “shell” of a second semiconductormaterial. A semiconductor nanocrystal core surrounded by a semiconductorshell is referred to as a “core/shell” semiconductor nanocrystal. Thesurrounding “shell” material will preferably have a bandgap energy thatis larger than the bandgap energy of the core material and may be chosento have an atomic spacing close to that of the “core” substrate.

In one embodiment, the nanocrystal of the invention presents acore/shell structure, i.e. the nanocrystal comprises a core and a shellof semiconducting material.

In one embodiment, the nanocrystal of the invention has a core/shellstructure, i.e. the core is totally coated by at least one layer ofinorganic material.

Preferably, said quantum dots are core/shell type I quantum dots. Saidtype I quantum dot can have a band alignment between the core and theshell such that the exciton created in the shell is transferred in thecore where it recombines radiatively.

In another embodiment, the nanocrystal of the invention comprises a coretotally coated by a first layer of inorganic material, said first layerbeing partially or totally surrounded by at least one further layer ofinorganic material.

In one embodiment, said core and said at least one layer of inorganicmaterial have the same composition or do not have the same composition.

In one embodiment, said core and said at least one layer of inorganicmaterial may be a semi-conductor from group IV, group IIIA-VA, groupIIA-VIA, group IIIA-VIA, group IA-MA-VIA, group IIA-VA, group IVA-VIA,group VIB-VIA, group VB-VIA, or group IVB-VIA.

In another embodiment, said core and said at least one layer ofinorganic material may comprise a material MxEy, wherein:

-   -   M is Zn, Cd, Hg, Cu, Ag, Al, Ga, In, Si, Ge, Pb, Sb, Pd, Fe, Au,        Ti, Bi, W, Mo, V or a mixture thereof,    -   E is O, S, Se, Te, N, P, As, or a mixture thereof, and    -   x and y are independently a decimal number from 0 to 5, at the        condition that when x is 0, y is not 0 and inversely.

In another embodiment, said core and said at least one layer ofinorganic material may be composed of a material from Si, Ge, CdS, CdSe,CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, PbS, PbSe, PbTe, CuInS₂,CuInSe₂, AgInS₂, AgInSe₂, CuS, Cu₂S, Ag₂S, Ag₂Se, Ag₂Te, InN, InP, InAs,InSb, In₂S₃, Cd₃P₂, Zn₃P₂, Cd₃As₂, Zn₃As₂, ZnO, AN, AlP, AlAs, AlSb,GaN, GaP, GaAs, GaSb, FeS₂, TiO₂, Bi₂S₃, Bi₂Se₃, Bi₂Te₃, MoS₂, WS₂, VO₂,and alloys and mixtures thereof.

In one embodiment, the core and/or the shell can be a semiconductormaterial including, but not limited to, those of the group II-VI (ZnS,ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, MgS, MgSe, MgTe, CaS,CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, and the like) and III-V(GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, and the like) and IV (Ge,Si, and the like) and IV-VI (PbS, PbSe) and I-III-VI-2 (CuInS₂, CuInSe₂,AgInS₂, AgInSe₂, CuGaS₂, CuGaSe₂, AgGaS₂, AgGaSe₂,) and L2-VI (Ag₂S,Ag₂Se) and IV-VI-2 (SnS₂, SnSe₂) and II-V (Cd₃P₂) and oxydes (ZnO)materials, and an alloy or a mixture thereof.

In another embodiment, the nanocrystal of the invention presents aheterostructure comprising a metallic material and semiconductormaterial.

According to one embodiment, the functionalizable/functionalizedmaterial of the invention comprises:

-   -   a material, preferably under the form of particles; and    -   at least one ligand according to the invention.

According to one embodiment, the material complexed by the ligand of theinvention is a nanoparticle, leading to afunctionalizable/functionalized nanomaterial.

According to one embodiment, the nanomaterial of the inventioncomprises:

-   -   a nanoparticle, preferably a nanocrystal; and    -   at least one ligand according to the invention.

According to an embodiment, the nanomaterial of the invention comprises:

-   -   a nanoparticle as described above, preferably a nanocrystal; and    -   at least one ligand according to the invention which is a        copolymer of formula (I):

H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R

-   -   wherein    -   A represents an anchoring monomer having a side-chain comprising        a first moiety M_(A) having affinity for the surface of a        nanocrystal;    -   B represents a hydrophilic monomer having a side-chain        comprising a second moiety M_(B) being hydrophilic;    -   n represents a positive integer, preferably an integer ranging        from 1 to 1000, preferably from 1 to 499, from 1 to 249 or from        1 to 99;    -   x and y represent each independently a percentage of n, wherein        x and y are different from 0% of n and different from 100% of n,        preferably ranging from more than 0% to less than 100% of n,        preferably from more than 0% to 80% of n, from more than 0% to        50% of n; wherein x+y is equal to 100% of n;    -   R represents:        -   a functional group selected from the group comprising —NH₂,            —COOH, —OH, —SH, —CHO, ketone, halide; activated ester such            as for example N-hydroxysuccinimide ester,            N-hydroxyglutarimide ester or maleimide ester; activated            carboxylic acid such as for example acid anhydride or acid            halide; isothiocyanate; isocyanate; alkyne; azide; glutaric            anhydride, succinic anhydride, maleic anhydride; hydrazide;            chloroformate, maleimide, alkene, silane, hydrazone, oxime            and furan;        -   a bioactive group selected from the group comprising avidin            or streptavidin; antibody such as a monoclonal antibody or a            single chain antibody; sugars; a protein or peptide sequence            having a specific binding affinity for an affinity target,            such as for example an avimer or an affibody (the affinity            target may be for example a protein, a nucleic acid, a            peptide, a metabolite or a small molecule), antigens,            steroids, vitamins, drugs, haptens, metabolites, toxins,            environmental pollutants, amino acids, peptides, proteins,            aptamers, nucleic acids, nucleotides, peptide nucleic acid            (PNA), folates, carbohydrates, lipids, phospholipid,            lipoprotein, lipopolysaccharide, liposome hormone,            polysaccharide, polymers, polyhistidine tags, fluorophores;            and    -   L represents a bound or a spacer selected from the group        comprising alkylene, alkenylene, arylene or arylalkyl linking        groups having 1 to 50 chain atoms, wherein the linking group can        be optionally interrupted or terminated by —O—, —S—, —NR₇—,        wherein R₇ is H or alkyl, —CO—, —NHCO—, —CONH— or a combination        thereof; or a spacer selected from the group comprising DNA,        RNA, peptide nucleic acid (PNA), polysaccharide, peptide.

According to an embodiment, the nanomaterial of the invention comprises:

-   -   a nanocrystal as described above; and    -   an outer layer including at least one ligand according to the        invention which is a copolymer of formula (I) as described        above.

In a preferred embodiment, the nanomaterial of the invention comprises aligand of formula (I) wherein R is an activated function such as forexample and activated ester or an activated carboxylic acid, preferablyan activated ester, more preferably N-hydroxysuccinimide ester.

In one embodiment of the invention, the nanomaterial of the inventioncomprises a nanocrystal complexed by the ligand of formula (II):

-   -   wherein    -   n, x, y, L and R are as defined in formula (I);    -   R_(A) represents a group comprising the first moiety M_(A)        having affinity for the surface of a nanocrystal;    -   R_(B) represents a group comprising the second moiety M_(B)        being hydrophilic;    -   R¹, R², R³, R⁴, R⁵ and R⁶ represent each independently H or a        group selected from the alkyl, alkenyl, aryl, hydroxyl, halogen,        alkoxy and carboxylate, amide.

In a specific embodiment, the nanomaterial of the invention comprises ananocrystal complexed by the ligand of formula (I-e′):

wherein n, x, y, L and R are as defined in formula (I) above.

In a further embodiment, the nanoparticle of the invention comprises ananocrystal complexed by the ligand of formula (I-f′):

wherein n, x, y and L are as defined in formula (I) above.

In a preferred embodiment, in formula (I-f), L represents an alkylenelinking group having 1 to 20 chain atoms and optionally interrupted orterminated by —O— or —S—. More preferably, L is of formula—S—(CH₂)_(n1), wherein n₁ is a positive integer ranging from 1 to 20,preferably 1 to 5, more preferably 1, 2 or 3. In another embodiment, Lrepresents an ethylene glycol derivative, preferably of formula—[CH₂—CH₂—O]_(n2)—(CH₂)_(n3)—S— wherein n₂ and n₃ are each independentlypositive integers ranging from 1 to 20, preferably 1, 2, 3, 4, 5, 6 7,8, 9 or 10, more preferably n₂ is equal to 8 and n₃ is equal to 2.

In another embodiment of the invention, the nanomaterial of theinvention comprises a ligand of formula (I) wherein R is a bioactivegroup, preferably a protein or an antibody.

Preferred embodiments relative to the ligand of formula (I) of theinvention described above apply to the ligand of formula (I) comprisedin the nanomaterial of the invention.

According to one embodiment, the nanomaterial of the invention comprisesa ligand of formula (I) wherein the number of ligand per dot is rangingfrom less than 100; preferably less than 50 ligands per dots; morepreferably less than 30 ligands per dots. In one embodiment, the numberof ligand per dot is about 20 ligands.

According to one embodiment, the nanomaterial of the invention comprisesa ligand of formula (I) wherein the number of fluorophores per dot isranging from less than 100; preferably less than 20; preferably is 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20fluorophores per dot; preferably is ranging from more than 0 to 1. Inone embodiment, the number of fluorophores per dot is 0.5.

Another object of the invention is a method for complexing at least oneligand of the invention to at least one material, preferably at leastone nanoparticle, more preferably at least one nanocrystal, comprising:

-   -   optionally a first step of complexation of the material,        preferably nanoparticles, more preferably nanocrystals, with an        intermediate ligand being a weakly binding ligand or a small        molecule (Meerwein's salt) ensuring the homogeneous dispersion        of the nanocrystal into a solvent miscible in part with water,    -   a step of monophasic exchange at about 40° C. to about 100° C.        in an aqueous medium overnight to remove the weak intermediate        ligand and replace it by the ligand of the invention.

In one embodiment, said weakly binding ligand or molecule may be MPA, ortrimethylsilylating agents, or trialkyl oxonium salts (Meerwein's salt),or any monothiol, or amine ligands.

In one embodiment, said first step is performed in basic chloroform andleads to the precipitation of the nanocrystal complexed to theintermediate ligand and to the homogeneous dispersion of the nanocrystalinto water at room temperature. In another embodiment, said first stepis performed in ethanol and leads to the precipitation of thenanocrystal complexed to the intermediate ligand.

In one embodiment, said second step is performed in an aqueous mediumsuch as 20 mM aqueous NaCl at about 50° C. to 75° C., preferably 60° C.,overnight, to remove the weak intermediate ligand and replace it by theligand of the invention.

In another embodiment, said method may further comprise anultrafiltration step and then an ultracentrifugation step in an aqueoussucrose gradient.

In the case wherein R represents a functional group in the ligand offormula (I), the process for manufacturing the nanomaterial of theinvention may further comprise a subsequent step of bio-conjugation tointroduce a bioactive group at the end of the polymeric chain of theligand.

In a further embodiment, some of the M_(A) moieties of the anchoringmonomers A of the ligand of the invention may be functionalized bybioactive groups, once the ligand has been complexed to the nanocrystal.

In an embodiment, the process for manufacturing the nanomaterial of theinvention comprises:

-   -   optionally a first step of complexation of nanocrystals with an        intermediate ligand being a weakly binding ligand or a small        molecule (Meerwein's salt) ensuring the homogeneous dispersion        of the nanocrystal into a solvent miscible in part with water;    -   a step of monophasic exchange at about 40° C. to about 100° C.        in an aqueous medium overnight to remove the weak intermediate        ligand and replace it by the ligand of the invention;    -   optionally one or more subsequent steps selected from:        -   in the case wherein R represents a functional group in the            ligand of formula (I), a step of bio-conjugation to            introduce a bioactive group at the end of the polymeric            chain of the ligand;        -   functionalization of some of the M_(A) moieties of the            anchoring monomers A of the ligand by bioactive groups.

By “some of the M_(A) moieties of the anchoring monomers” it is referredto less than 70% of the total number of M_(A) moieties.

The nanomaterial of the invention may be obtained by the complexation ofthe ligand of formula (I) of the invention with a nanocrystal. Oncecomplexed with the nanocrystal, the ligand of formula (I) may bemodified, especially by activation of functional group R present at oneend of the ligand. Moreover, the ligand of formula (I) may be modifiedby conjugation of a bioactive group to the functional group or activatedfunctional group present at one end of the ligand, leading tofunctionalized ligand of formula (I).

According to one embodiment, the nanomaterial of the invention isactivated by modifying the terminal end R of the ligand of formula (I)under the form of a terminal N-hydroxysuccinimide ester. Such activationenables the conjugation of bioactive groups comprising an amino group.

Another object of the invention is a water-soluble compositioncomprising at least one quantum dot, nanoplatelet or quantum dot havingits lateral dimensions larger than its thickness, complexed with atleast one ligand of the invention.

Another object of the invention is the use of said quantum dot,nanoplatelet or quantum dot having its lateral dimensions larger thanits thickness, complexed with at least one ligand of the invention forbioimaging, biotargeting, medical imaging, biosensing.

Thus, it is readily apparent that said complexes find use in a varietyof assays where other, less reliable, labeling methods have typicallybeen used, including, without limitation, fluorescence microscopy,fluorescence histology, fluorescence cytology, fluorescence pathology,cell labeling, flow cytometry, western blotting, Fluorescence ResonanceEnergy Transfer (FRET), immunocytochemistry, Fluorescence In SituHybridization (FISH) and other nucleic acid hybridization assays, signalamplification assays, DNA and protein sequencing, immunoassays such ascompetitive binding assays and ELISAs, immunohistochemical analysis,protein and nucleic acid separation, homogeneous assays, multiplexing,high throughput screening, chromosome karyotyping, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are ¹H NMR spectra recorded in D₂O showing the monomerconsumption during the polymer synthesis, between the initial state ofthe polymerization (FIG. 1A) and the end of the polymerization (FIG.1B).

FIGS. 2A et 2B are photographs of coated dots QD-PEG-SA, QD-SA andQD-PEG-COOH observed without any apparatus after reaction withbiotin-coated agarose beads.

FIG. 2C is a photograph of coated dots QD-PEG-SA, QD-SA and QD-PEG-COOHobserved by microscopy after reaction with biotin-coated agarose beads.

EXAMPLES

The present invention will be better understood with reference to thefollowing examples. These examples are intended to representative ofspecific embodiments of the invention, and are not intended as limitingthe scope of the invention.

ABBREVIATIONS

AIBN: azobisisobutyronitrile;APMA.HCl: N-(3-aminopropyl)methacrylamide hydrochloride;

CTA: Chain Transfer Agent;

DCC: dicyclohexylcarbodiimide;EDC: 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride;LA: 5-(1,2-dithiolan-3-yl)pentanoic acid, also known as lipoic acid;MES buffer: 2-(N-morpholino)ethanesulfonic acid aqueous buffer;

MFA: N-methylformamide;

MPA: 3-mercaptopropionic acid;

NHS: N-Hydroxysuccinimide;

PEG: poly(ethylene glycol);

QD(s): Quantum Dot(s);

SA: streptavidin;SPP: 3-sulfopropyldimethyl-3-methacrylamidopropylammonium inner salt.

Materials and Instrumentation

Streptavidin was purchased from Biospa; APMA.HCl was purchased fromTebu-bio; SPP and3-[3-methacrylamidopropyl-(dimethyl)ammonio]propane-1-sulfonate), fromRaschig GmbH (RaleMer SPP); all other chemicals used therein werepurchased from Sigma-Aldrich. All of these purchased chemicals were usedwithout further purification unless otherwise specified. Chromatographyon silica was carried out on Kieselgel 60 (230-240 mesh, Merck) andanalytical TLC was performed on Merck precoated silica gel (60 F₂₅₄) ¹HNMR spectrum was recorded on a Bruker Avance DPX 400 spectrometer at400.13 MHz. Chemical shifts (δ) are expressed in ppm and couplingconstant (J) in hertz. Absorption measurements were carried out with aCary 5E UV-vis-NIR spectrophotometer (Varian).

Example 1 Ligand Synthesis Synthesis of monomer A(5-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)-pentanamide)

To a suspension of APMA.HCl (2 g, 11.2 mmol) in dichloromethane (20 mL)was added triethylamine (2.5 mL, 17.9 mmol). Methanol (2 mL) wasintroduced to obtain complete solubilization. A solution of LA (2.76 g,13.4 mmol) in dichloromethane (5 mL) was then added, followed by NHS(1.58 g, 13.8 mmol) in one portion. The reaction mixture was cooled downto 0° C. with an ice bath and a solution of DCC (3.00 g, 14.4 mmol) indichloromethane (10 mL) was injected dropwise. The medium was warmed upto room temperature and further stirred overnight. A pale yellowsolution containing a white precipitate was obtained. The solution waswashed by a 0.1 M aqueous HCl solution (2×50 mL), deionized water (1×50mL) and a 0.2 M aqueous NaOH solution (2×50 mL). The organic phase wasseparated, dried over MgSO₄, filtrated and concentrated under reducedpressure. The crude residue was purified by chromatography on silica(eluent: hexane/ethyl acetate 1/4, then hexane/acetone 1/1) to give A(2.88 g, 8.71 mmol, 78%) as a pale yellow solid. R₁=0.37 (hexane/acetone1/1); ¹H NMR (CDCl₃, 400 MHz): δ 7.03 (sl, 1H); 6.87 (sl, 1H); 5.72 (s,1H); 5.29 (s, 1H); 3.53-3.39 (m, 1H); 3.29-3.20 (m, 4H); 3.14-3.01 (m,2H); 2.43-2.35 (m, 1H); 2.18 (t, J=8.0 Hz, 2H); 1.92 (s, 3H); 1.88-1.80(m, 1H); 1.68-1.55 (m, 6H); 1.48-1.33 (m, 2H).

Synthesis of the Ligand

The polymerization step consisted of the radical copolymerization of twomethacrylamides: one containing the precursor of a dithiol anchoringfunction (monomer A, obtained as described above), the other including asulfobetaine group (monomer B, SPP commercially available).

Due to mismatching monomers' solubilities, the solvent used for thesepolymerizations was acetic acid. Various A/B molar ratios have beentested between 10/90 and 50/50.

The amounts of initiating agent AIBN(2,2′-Azobis(2-methylpropionitrile)) and of CTA were chosen in variousmolar equivalents relative to the total amount of monomers, in order toform various length chains. Various monomer/CTA molar ratios have beentested between 10/1 and 40/1. The monomers conversion rates weredetermined by ¹H NMR in D₂O (classically over 90%).

Characterization of the products by NMR confirmed the M_(A)/M_(B) molarratio by comparison of the acrylamide peaks between the initial state ofthe polymerization (FIG. 1A) and the end of the polymerization (FIG.1B).

A general procedure is given for the synthesis a ligand with x=2 andn=10.

Monomer B (SPP, 1.17 g, 4 mmol, 4 equiv.), monomer A(5-(1,2-dithiolan-3-yl)-N-(3-methacrylamidopropyl)pentanamide, 331 mg, 1mmol, 1 equiv.) and CTA (0.5 mmol, 0.5 equiv.) were dissolved in aceticacid (20 mL) in a sealed septum flask. The mixture was degassed withargon and then heated at 60° C. A solution of AIBN (82 mg, 0.5 mmol, 0.5equiv.) in acetic acid (2 mL) under argon atmosphere was further addedin one portion. The mixture was stirred overnight at 60° C. Acetic acidwas evaporated under reduced pressure. To remove residual acetic acidtraces, the residue was dissolved in 20 mL of deionized water andevaporated under reduced pressure (two times). The residue was thendissolved in 20 mL of deionized water and extracted three times with 20mL of dichloromethane. The aqueous phase was precipitated in 9-foldexcess of ethanol. The precipitated polymer was separated bycentrifugation (50 mL centrifuge tubes, 2500 rpm, 10 min), washed 2times with ethanol and then dried overnight under vacuum. The polymerwas obtained as a yellow-brown solid (950 mg, 61%).

Chain Transfer Agents (CTA) 0.5 mmol Structures Mercaptopropionic acid(MPA) 42 μL

Cysteamine 38 mg

O-(2-carboxyethyl)- O′-(2-mercaptoethyl) heptaethylene glycol 229 mg

In the case wherein the ligand is obtained by polymerization with“mercapto-carboxilic acid containing compounds” as CTA, the ligand isreferred to as “ligandCOOH”. Especially, in the case wherein the ligandis obtained by polymerization with mercaptoproprionic acid as CTA, theligand is referred to as “ligand-(CH₂)₂COOH” and in the case wherein theligand is obtained by polymerization with a CTA comprising a PEG moiety,the ligand is referred to as “ligand-PEG-COOH”.

In the case wherein the ligand is obtained by polymerization with“mercapto-amino containing compounds” as CTA, the ligand is referred toas “ligandNH₂”.

Example 2 Quantum Dot Synthesis CdSe/CdS/ZnS QDs Synthesis

600-nm-emitting CdSe/CdS/ZnS QDs were synthesized using slightmodifications of previously published procedures. CdSe cores weresynthesized by reaction of trioctylphosphine selenide and cadmium oleatein octadecene, oleylamine and trioctylphosphine oxide. Three monolayersof CdS shell, followed by two monolayers of ZnS, were grown usingcadmium oleate, zinc oleate and sulfur diluted in octadecene followingthe SILAR (Successive Ionic Layer Adsorption and Reaction) procedure.

Example 3 Nanocrystal Complexation Ligand Exchange: Standard Procedure

“Classical” biphasic cap exchange with CdSe/CdS/ZnS core/shell QDssolubilized in chloroform did not succeed. The poor solubility of theligand of the invention in chloroform and the low partition coefficientbetween the two solvents could explain the difficult phase transfer ofthe QDs.

To overcome this problem, a two-step process was chosen. A firstexchange was performed using pure mercaptopropionic acid (MPA), onas-synthesized QDs precipitated in ethanol. The QDs were kept overnightat 60° C. in order to have QDs surface was saturated by MPA. The excessof MPA was removed and QDs were dispersed in DMF. The MPA were thendeprotonated using a large excess of tert-butoxide. The QDs became theninstable in organic solvents and were precipitated and washed withethanol. QDs were then suspended in a sodium tetraborate (pH 9, 10 mM)water-based buffer. To this homogeneous dispersion, an aqueous solutionof previously reduced ligand of the invention (by NaBH₄) was added toperform the second ligand exchange. The aqueous medium was keptovernight at 60° C. to move from the weak intermediate QD covered by MPAto QD-ligand. The polymer excess was removed by Vivaspin® filtration.The QD-ligand did not show any change in quantum yield after the ligandexchange.

General Procedure

CdSe/CdS/ZnS core/shell QDs in hexane (0.2-2 nmol respectively for650-550 nm QDs) were precipitated with ethanol (0.5 mL) and centrifuged(13000 rpm, 5 min). The supernatant was removed. The QDs were dispersedin 3-mercaptopropionic acid (MPA) (0.2 mL). The mixture was sonicated toobtain a homogenous dispersion. The QDs dispersion was stored at 60° C.overnight to perform first cap exchange. The QDs were centrifuged (13000rpm, 2 min) and the MPA phase was discarded. The QDs were dispersed inDMF (0.2 mL) under sonication. 2 mg of potassium tert-butoxide wereadded and QDs dispersion was sonicated (1 min). The mixture wascentrifuged (13000 rpm, 2 min). The uncolored DMF phase was discarded.The precipitated QDs were washed twice with ethanol (2×0.5 mL EtOH). TheQDs were dispersed in sodium tetraborate (pH9 10 mM). Typically, at thisstep, QDs colloidal dispersion was clear. 200 μL of aqueous solution ofthe ligand of the invention (10 mg/mL), previously reduced 30 min withNaBH₄ (1 mg/mg of polymer), were added to QDs dispersion. The aqueousQDs dispersion was stored at 60° C. overnight to perform the second capexchange. The excess of free ligand and reagents were removed by threewashing by membrane ultrafiltration (Sartorius Vivaspin®500 μLdisposable filter—cutoff 100 kDa) at 13000 rpm in 20 mM aqueous NaCl.QDs-ligand were finally taken up in 20 mM aqueous NaCl.

In the case wherein the ligand is a ligandCOOH, as in example 1,resulting coated QDs are referred to as “QDs-ligandCOOH”.

Example 4 Activation of the Ligand on the Nanocrystal

In the case wherein the ligand of the invention is obtained bypolymerization with “mercapto-carboxilic acid containing compounds” asCTA (for example: mercaptopropionic acid orO-(2-Carboxyethyl)-O′-(2-mercaptoethyl)heptaethylene glycol), an acidicfunction is advantageously introduced at one extremity of the ligand(respectively “ligand(CH₂)₂COOH” and “ligand-PEG-COOH”).

Ligand exchange using these ligandCOOH has been studied in order toprovide biocompatible coated QDs presenting carboxylic acidic function,QDs-ligandCOOH. First, reactive N-hydroxysuccinimide (NHS) estersthereof (“QD-ligandNHS”) were prepared and purified. Then, theseactivated QDs have been used to functionalize QDs with protein (forexample: streptavidin or antibodies).

Washing Before Freeze-Drying: Standard Procedure

QDs-ligandCOOH in 20 mM aqueous NaCl were washed three times by membraneultrafiltration at 13000 rpm using a Sartorius Vivaspin®500 μLdisposable filter (cutoff 100 kDa) in pure water. QDs-ligandCOOH werefinally taken up in pure water for freeze-drying.

Activation of the Carboxylic Acidic Function of the Polymer on QDs:Standard Procedure

Freeze-dried QD-ligandCOOH (2.5 mg) were dispersed in pure water (50 μL)at room temperature. In parallel, EDC (5 mg, 30 μmol) and NHS (5 mg, 44μmol) were dissolved in MES buffer 0.2 M pH 5.5 (1 mL). 20 μL of thissolution are added to the dispersion of QD and immediately after 180 μLof MFA are added. The reaction was stirred overnight at room temperaturebefore precipitation in acetonitrile (1 mL). The colored precipitateobtained after centrifugation (13000 rpm, 2 min) was washed twice inacetonitrile (1 mL) before drying under vacuum. QDs-ligandNHS wereconserved under inert atmosphere at −18° C.

Biomolecules Functionalization of QDs:

Several experiments were carried out starting from eitherQDs-ligand-COOH or QDs-ligand-NHS.

QDs-ligand-(CH₂)₂—COOH represents quantum dots coated with a ligandcopolymer wherein the end carboxylic function is from3-mercaptopropionic acid. QDs-ligand-(CH₂)₂—NHS correspond to thecorresponding dots after the reaction with N-hydroxysuccinimide.

QDs-ligand-PEG-COOH represents quantum dots coated with a ligandcopolymer wherein the end carboxylic function is from a CTA comprising aPEG moiety; especially from(2-carboxyethyl)-O′-(2-mercaptoethyl)heptaethylene glycol.QDs-ligand-PEG-NHS corresponds to the corresponding dots after thereaction with N-hydroxysuccinimide.

Standard Procedure from QDs-ligandNHS

Dried QDs-ligandNHS (2.5 mg) were dispersed in 120 μL streptavidine orantibody solution (10 mg/mL in aqueous NaHCO₃ 0.2 M pH 8.4). Proteinexcess was eliminated by ultracentrifugation on sucrose gradient(40%-10%). QDs-proteins/QDs-antibody were finally taken up in 0.2Maqueous NaHCO₃.

Characterizations Biotin Test

First the quantum dots functionalized by streptavidin were tested withbiotin-coated agarose beads in order to evaluate the achievement of thefunctionalization. The results are shown Table 1 and FIGS. 2A, 2B and2C.

TABLE 1 Results of the test on biotin-coated agarose beads. Reactionwith biotin- coated Reagent 1 Reagent 2 Obtained agarose (coated quantumdots) (protein-NH₂) product beads* QDs-ligand-PEG-COOH StreptavidinQDs-PEG-SA + QDs-ligand-(CH₂)₂-COOH Streptavidin QDs-SA 0QDs-ligand-PEG-COOH — QDs-PEG-COON 0 QDs-ligand-(CH₂)₂-COOH —QDs-(CH₂)₂-COOH 0 *+: positive result; 0: negative result

In this test, the high affinity between streptavidin and biotin leads tofluorescence.

The results of Table 1 show that when quantum dots are coated with aligand comprising a PEG moiety (QDs-ligand-PEG-COOH), theirfunctionalization with streptavidin leads to fluorescent agarose beads(+).

In the case wherein quantum dots are coated with a ligand comprising a—S—(CH₂)₂—COOH end obtained from mercaptopropionic acid(QDs-ligand-(CH₂)₂—COOH), the reaction between the resulting quantumdots and the agarose beads does not lead to fluorescent beads.

These results show that when the ligand is ended by —S—(CH₂)₂—COOH, thefunctionalization with streptavidin fails whereas in the case whereinthe ligand comprises a PEG moiety, the functionalization of theQDs-PEG-COOH is successfully achieved.

Without willing to be bound by a theory, the Applicant thinks that thesize of the spacer affects the functionalization of the coated-quantumdots. The skilled human in the art knows that carboxylic function hasgood affinity for the surface of dots. Thus, increasing the size of thespacer L would have favored the coiling of the end of the ligand chainon the dots surface, preventing the functionalization by a protein, afluorophore or an antibody.

Unexpectedly, these experiments show that an enough long spacer isrequired to implement the functionalization of the QDs-NHS with aprotein or an antibody.

Number of Fluorophores by Quantum Dot

Functionalized quantum dots were analyzed by HPLC with an absorbancedetector at 254 nm or a fluorescence detector (emission parameters:L_(exc.)=630 nm and LF=650 nm). The number of fluorophores grafted on aquantum dots is calculated by the ratio between the absorption band ofQDs (at 350 nm) and the absorption band of fluorophores (at 650 nm).

The results are shown in the following table:

Functionalized QDs Number of fluorophores (F) by QD QDs-PEG-F 0.5 QDs-F0

These results show that when quantum dots are coated with a ligandcomprising a -PEG-COOH moiety and then functionalized with a fluorophore(QDs-PEG-F), the functionalization reaction is successfully carried outand the average number of flurophores per dot is 0.5.

In the case wherein quantum dots are coated with a ligand comprising a—(CH2)2-COOH end and then functionalized with a fluorophore (QDs-F), thereaction of functionalization fails.

In conclusion, these results confirm that the design of the ligand endis important. Especially, a too short spacer L does not allow thefunctionalization of the ligand-coated QDs.

1-15. (canceled)
 16. A nanomaterial comprising: a nanoparticle; and atleast one ligand which is a copolymer of formula (I):H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R wherein A represents an anchoringmonomer having a side-chain comprising a first moiety M_(A) havingaffinity for the surface of a nanocrystal; B represents a hydrophilicmonomer having a side-chain comprising a second moiety M_(B) beinghydrophilic; n represents a positive integer; x and y represent eachindependently a percentage of n, wherein x and y are different from 0%of n and different from 100% of n; wherein x+y is equal to 100% of n; Rrepresents: a functional group selected from the group comprising —NH₂,—COOH, —OH, —SH, —CHO, ketone, halide; activated ester; activatedcarboxylic acid; isocyanate; alkyne; azide; glutaric anhydride, succinicanhydride, maleic anhydride; hydrazide; chloroformate, maleimide,alkene, silane, hydrazone, oxime and furan; a bioactive group selectedfrom the group comprising avidin or streptavidin; antibody; sugars; aprotein or peptide sequence having a specific binding affinity for anaffinity target; and L represents a bound or a spacer selected from thegroup comprising alkylene, alkenylene, arylene or arylalkyl linkinggroups having 1 to 50 chain atoms.
 17. The nanomaterial according toclaim 16, wherein said nanoparticle is a nanocrystal and wherein thenanocrystal is a 0D, 1D, or 2D nanocrystal.
 18. The nanomaterialaccording to claim 16, wherein said nanoparticle is selected in thegroup of a nanosheet, a nanorod, a nanoplatelet, a nanoplate, ananoprism, a nanowall, a nanodisk, a nanoparticle, a nanowire, ananopowder, a nanotube, a nanotetrapod, a nanoribbon, a nanobelt, ananoneedle, a nanocube, a nanoball, a nanocoil, a nanocone, ananopiller, a nanoflower, or a quantum dot.
 19. The nanomaterialaccording to claim 16 wherein the ligand is of formula (II):

wherein n, x, y, L and R are as defined in claim 16; R_(A) represents agroup comprising the first moiety M_(A) having affinity for the surfaceof a nanocrystal; R_(B) represents a group comprising the second moietyM_(B) being hydrophilic; R¹, R², R³, R⁴, R⁵ and R⁶ represent eachindependently H or a group selected from the alkyl, alkenyl, aryl,hydroxyl, halogen, alkoxy and carboxylate, amide.
 20. The nanomaterialaccording to claim 16, wherein the ligand is of formula (I-e′):

wherein n, x, y, L and R are as defined in claim
 16. 21. Thenanomaterial according to claim 16, wherein the ligand is of formula(I-f′):

wherein n, x, y and L are as defined in claim
 16. 22. A ligand which isa copolymer of general formula (I):H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R wherein A represents an anchoringmonomer having a side-chain comprising a first moiety M_(A) havingaffinity for the surface of a nanocrystal; B represents a hydrophilicmonomer having a side-chain comprising a second moiety M_(B) beinghydrophilic; n represents a positive integer; x and y represent eachindependently a percentage of n, wherein x and y are different from 0%of n and different from 100% of n; R represents: a functional groupselected from the group comprising —NH₂, —COOH, —OH, —SH, —CHO, ketone,halide; activated ester; activated carboxylic acid; isothiocyanate;isocyanate; alkyne; azide; glutaric anhydride, succinic anhydride,maleic anhydride; hydrazide; chloroformate, maleimide, alkene, silane,hydrazone, oxime and furan; and a bioactive group selected from thegroup comprising avidin or streptavidin; antibody; sugars; a protein orpeptide sequence having a specific binding affinity for an affinitytarget; and L represents a bound or a spacer selected from the groupcomprising alkylene, alkenylene, arylene or arylalkyl linking groupshaving 1 to 50 chain atoms.
 23. The ligand according to claim 22, ofgeneral formula (II):

wherein n, x, y, L and R are as defined in claim 22; R_(A) represents agroup comprising the first moiety M_(A) having affinity for the surfaceof a nanocrystal; R_(B) represents a group comprising the second moietyM_(B) being hydrophilic; R¹, R², R³, R⁴, R⁵ and R⁶ represent eachindependently H or a group selected from the alkyl, alkenyl, aryl,hydroxyl, halogen, alkoxy and carboxylate, amide.
 24. The ligandaccording to claim 22, of formula (I-e):

wherein n, x, y, L and R are as defined in claim
 22. 25. The ligandaccording to claim 22, of formula (I-f):

wherein n, x, y and L are as defined in claim
 22. 26. The ligandaccording to claim 22, wherein L represents an alkylene linking grouphaving 1 to 20 chain atoms.
 27. The ligand according to claim 22,wherein R represents —COOH or —NH₂.
 28. A water-soluble compositioncomprising nanomaterials comprising: a nanoparticle; and at least oneligand which is a copolymer of formula (I):H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R wherein A represents an anchoringmonomer having a side-chain comprising a first moiety M_(A) havingaffinity for the surface of a nanocrystal; B represents a hydrophilicmonomer having a side-chain comprising a second moiety M_(B) beinghydrophilic; n represents a positive integer; x and y represent eachindependently a percentage of n, wherein x and y are different from 0%of n and different from 100% of n; wherein x+y is equal to 100% of n; Rrepresents: a functional group selected from the group comprising —NH₂,—COOH, —OH, —SH, —CHO, ketone, halide; activated ester; activatedcarboxylic acid; isocyanate; alkyne; azide; glutaric anhydride, succinicanhydride, maleic anhydride; hydrazide; chloroformate, maleimide,alkene, silane, hydrazone, oxime and furan; a bioactive group selectedfrom the group comprising avidin or streptavidin; antibody; sugars; aprotein or peptide sequence having a specific binding affinity for anaffinity target; and L represents a bound or a spacer selected from thegroup comprising alkylene, alkenylene, arylene or arylalkyl linkinggroups having 1 to 50 chain atoms.
 29. A method for bioimaging,biotargeting, medical imaging or biosensing comprising applying aneffective amount of a nanomaterial according to claim
 16. 30. A methodfor manufacturing a ligand which is a copolymer of general formula (I):H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R wherein A, B, R, n, x, y and L are asdefined in claim 22, wherein said method comprises polymerizing ananchoring monomer A and a hydrophilic monomer B in presence of aninitiator and a chain transfer agent (CTA), wherein anchoring monomer Aand a hydrophilic monomer B are as defined in claim
 22. 31. A method formanufacturing the nanomaterial according to claim 16 comprising: a firststep of complexation of nanocrystals with an intermediate ligand being aweakly binding ligand or a small molecule ensuring the homogeneousdispersion of the nanocrystal into a solvent miscible in part withwater; a step of monophasic exchange at about 40° C. to about 100° C. inan aqueous medium overnight to remove the weak intermediate ligand andreplace IL by the ligand which is a copolymer of general formula (I):H—P[(A)_(x)-co-(B)_(y)]_(n)-L-R wherein A represents an anchoringmonomer having a side-chain comprising a first moiety M_(A) havingaffinity for the surface of a nanocrystal; B represents a hydrophilicmonomer having a side-chain comprising a second moiety M_(B) beinghydrophilic; n represents a positive integer; x and y represent eachindependently a percentage of n, wherein x and y are different from 0%of n and different from 100% of n; R represents: a functional groupselected from the group comprising —NH₂, —COOH, —OH, —SH, —CHO, ketone,halide; activated ester; activated carboxylic acid; isothiocyanate;isocyanate; alkyne; azide; glutaric anhydride, succinic anhydride,maleic anhydride; hydrazide; chloroformate, maleimide, alkene, silane,hydrazone, oxime and furan; and a bioactive group selected from thegroup comprising avidin or streptavidin; antibody; sugars; a protein orpeptide sequence having a specific binding affinity for an affinitytarget; and L represents a bound or a spacer selected from the groupcomprising alkylene, alkenylene, arylene or arylalkyl linking groupshaving 1 to 50 chain atoms.
 32. A method for bioimaging, biotargeting,medical imaging or biosensing comprising applying an effective amount ofthe water-soluble composition according to claim
 28. 33. Thenanomaterial of claim 16, wherein the linking group is interrupted orterminated by —O—, —S—, —NR₇—, wherein R₇ is H or alkyl, —CO—, —NHCO—,—CONH— or a combination thereof; or a spacer selected from the groupcomprising DNA, RNA, peptide nucleic acid (PNA), polysaccharide,peptide.
 34. The ligand of claim 22, wherein the linking group isinterrupted or terminated by —O—, —S—, —NR₇—, wherein R₇ is H or alkyl,—CO—, —NHCO—, —CONH— or a combination thereof; or a spacer selected fromthe group comprising DNA, RNA, peptide nucleic acid (PNA),polysaccharide, peptide.
 35. The ligand according to claim 26, wherein Lis interrupted or terminated by —O— or —S—.